Northstar 958 User guide

NORTHSTAR

958 Integrated

Navigation System

Operator’s Manual

P/N GM958UM Revision A

Limited warranty policy

Northstar Technologies, Inc. warrants the Northstar 958 to be free from defects in mate­rials and workmanship for a period of two (2) years. This warranty applies to the original
purchaser and to any subsequent owner during the warranty period, which begins on the
date of shipment of the 958, F.O.B. Acton, Massachusetts, to an authorized Northstar
dealer.

Systems may not be returned to Northstar without a Returned Materials Authorization
(RMA) number. Call your Northstar dealer or Northstar for instructions.

During the 958’s warranty period, Northstar will repair or replace, at its option, any part of
the 958 it finds to be defective due to faulty material(s) or workmanship. All such repairs
and/or replacements will be promptly performed by Northstar free-of-charge to the owner,
excluding freight costs incurred in shipping to the factory. Return shipments from North­star to points within the United States are made via ground transportation, freight prepaid.
Special shipping charges (overnight, two-day, and so on) are the responsibility of the
owner.

To be covered by this warranty, the Northstar equipment must have been in normal use.
This warranty does not apply to 958’s with defects caused by improper installation, phys­ical damage, abuse, tampering, lightning or other abnormal electrical discharge, or to
958’s with defaced or altered serial numbers, or to 958’s repaired by unauthorized persons
or repaired in a manner that violates Northstar’s recommended service procedures.

All repairs and/or replacements made under this warranty must be performed at North­star’s facilities in Acton, Massachusetts. Performance of warranty work elsewhere will not
be authorized, and Northstar will not pay for any charges for such work. Northstar will not
be responsible for payment of any charges imposed by a Northstar dealer or other party
for services requested by and/or performed for a 958’s owner in connection with this
warranty. Such services might include removal of the 958 from a vessel, inspection, pack­aging, handling, reinstallation, and the like.

Northstar Technologies assumes no responsibility for any consequential losses of any
nature with respect to any of its products or services sold, rendered, or delivered. The
foregoing is the only warranty expressed or implied. No other warranty exists.

CAUTION!

Northstar products are designed to be very useful navigation
tools, but they are not substitutes for good seamanship. The
prudent navigator should never rely on any single device as the
sole source of navigation guidance. Exercise caution and good
judgment when underway.

CAUTION!

The electronic chart is an aid to navigation designed to facili­tate the use of authorized government charts, not replace
them. Only official government charts and notices to mariners
contain all the information needed for safe navigation, and, as
always, the user is responsible for their prudent use.

Contents

1 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Welcome to the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Using this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Obtaining technical support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Turning the 958 on and off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Displaying the chart screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Using chart data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Displaying detailed position information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Using demo mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Going to a quick waypoint now . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2 Introducing the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Introducing the controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Introducing the display screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Introducing radar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Introducing the echo sounder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Introducing alarms, TideTrack, and video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Maintaining the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Interfacing the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3 Using the Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Using the PWR key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Using the five function keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Using the CURSOR PAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Using the SAVE key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the MOB key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the alphanumeric KEYPAD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Using the menu keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Using the BRIGHTNESS key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Using the IN and OUT keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4 Using the Chart Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Understanding electronic charts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Understanding nav aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Zooming in and out. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Controlling the cursor on the chart screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Comparing vessel and browse modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

958 Operator’s Manual, Rev. A Page i

Splitting the screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Controlling the screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Rotating the chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Setting up the chart screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Using distance and bearing mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5 Determining Your Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Displaying position, COG, and speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using DGPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Using loran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Using Phantom Loran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

6 Understanding the Waypoints Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Introducing waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoint coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Creating new waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Creating avoidance-area waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Editing waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Updating waypoint coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Moving waypoints/routes between units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Transferring waypoints to and from a PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

7 Understanding the Routes Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Introducing routes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Creating routes from the chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Creating routes from a waypoints list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Saving a route as you travel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Editing a route . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

8 Understanding Waypoint/Route Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109

Navigating to waypoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Steering to a waypoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Navigating along routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Restarting the course line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

9 Using the Nav Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121

Introducing the nav log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Changing your trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Stopping and restarting navigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Page ii 958 Operator’s Manual, Rev. A

10 Understanding Radar Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125

Understanding how radar works. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Displaying and controlling radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Turning radar on and off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Overlaying radar on the chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Changing scale and rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Using the main radar keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

Using the adjust radar keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Using the radar markers keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

11 Alarms, TideTrack, and Video Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143

Understanding alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Understanding TideTrack™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Using the video display option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

12 Setting Up Your 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163

Changing your display settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Changing your navigation settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

Changing your receiver settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

Changing your port settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Setting up the sounder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Setting up radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Installing Software Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Displaying manufacturer’s information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Changing the time zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

Appendix A - Understanding GPS, WAAS, and Radar . . . . . . . . . . . . . . . . . . . . . . . . .183

Introducing GPS and WAAS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

Introducing radar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Appendix B - System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191

Appendix C - Geodetic Datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197

Appendix D - Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .211

Page iii 958 Operator’s Manual, Rev. A

Page iv 958 Operator’s Manual, Rev. A

1

his chapter introduces this manual, familiarizes you with

T

the 958’s navigation functions and CHART screen features,
and explains how to display basic positioning information on
the CHART screen.

Getting Started

Welcome to the 958 . . . . . . . . . . . . . . . . . . . . . . . . . 2

Using this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Obtaining technical support . . . . . . . . . . . . . . . . . 3

Turning the 958 on and off . . . . . . . . . . . . . . . . . . 5

Displaying the chart screen . . . . . . . . . . . . . . . . . . 7

Using chart data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Displaying detailed position information . . . 13

Using demo mode . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Going to a quick waypoint now . . . . . . . . . . . . . 16

958 Operator’s Manual, Rev. A Page 1

Chapter 1 - Getting Started

Welcome to the 958

Congratulations on your purchase of the Northstar 958
Integrated Naviagation System! The 958 is a full-featured color
GPS/vector charting system, which is extremely easy to use,
but meets your marine navigation needs in a comprehensive,

The 958 has several require­ments that must be met to
ensure safe and proper opera­tion. To ensure that all critical
installation parameters are
met, installation and interfac­ing of the 958 should be han­dled by a marine technician
using the guidelines found in
the Northstar 958 Installation
Manual.

logical manner.

The 958 combines GPS with WAAS or optional radiobeacon
differential position navigation, and offers a high-resolution

10.4” full-color screen, Navionics cartography, radar, a video
overlay feature, optional fish finding capability using
Northstar’s add-on echo sounder (fishfinder), and many other
features.

The 958 anticipates your most common requests for
navigation information, so accessing most functions requires
just one or two keypresses. By reducing the attention required
to navigate, you can devote more time to other aspects of your
trip.

For information on installing, interfacing, and troubleshooting
the 958, please see the Northstar 958 Installation Manual (part
number GM958IM) or contact your local authorized Northstar
dealer.

Using this manual

This manual complements the 958’s ease-of-use by describing
and illustrating its various functions in a format that’s
conducive to fast learning and safe operation.

The manual’s sections are grouped by related functions,
starting with an overview of the basic control-panel layout and
function commands, and moving to more advanced waypoint
and route navigation operations. Sample screens are provided
to show how each function appears on the 958’s display
screen.

Once you start using the 958, you’ll discover that you can use
it without constantly referring to this manual. After you’ve
read the manual once, you probably won't have to refer to it
very often.

Page 2 958 Operator’s Manual, Rev. A

Chapter 1 - Getting Started

Conventions

This manual uses certain conventions to provide a consistent
way to recognize specific information, as follows:

• is the universal caution symbol for caution and
warning information related to your personal safety or
possible damage to the system. The

WARNING

them!

NOTE

•
contain valuable information that’s purposely highlighted
so you won’t miss it while reading the main text.

• KEY is the type style used to refer to the function keys
(the five main keys located below the left side of the
display screen) as well as the six menu keys (located in a
vertical row on the right side of the 958).

DISPLAY TEXT

•
on the display screens.

Sample 958 screen

•
display screens.

•

Figure 1

• A bulleted list contains a series of related items or topics.

• A numbered list contains a series of steps in a procedure.

• The command “Press a button or key” means push briefly
and release, unless otherwise specified.

• Latitude and longitude coordinates are collectively
referred to as lat/lon coordinates or just lat/lon.

boxes contain critical information—please read

is the type style used for titles of notes. These notes

is the type style used for text that appears

is the type style used for captions of

is the type style used for captions of figures.

CAUTION

and

Obtaining technical support

After you’ve follow the instructions in this manual, if you need
technical support or have any other questions, you can
contact Northstar by email, fax, phone, or U.S. mail as follows:

Table 1: Contacting Northstar

Email

:

Service: [email protected]
Sales: [email protected]

958 Operator’s Manual, Rev. A Page 3

Chapter 1 - Getting Started

Table 1: Contacting Northstar (continued)

Fax

:

Service: 978/897-1595
Sales: 978/897-7241

Telephone:

Main number: 978/897-6600 or 800/628-4487

U.S. mail:

30 Sudbury Road
Acton, MA 01720 USA

Website:

www.northstarcmc.com (you can send email to
Northstar from this site).

Hearing from you

Service and repair

Your feedback is important and helps Northstar ensure that
this manual is a valuable resource for all 958 users. Send your
questions, comments, or suggestions about this manual to:

[email protected]

In case of a 958 operating problem, you can contact your
dealer or return the 958 to Northstar for diagnosis and repair.
Before returning the 958 for repair, you may want to save your
waypoints and routes. When describing an operating problem,
be as complete and accurate as possible. Be sure to have your
958’s serial number and software revision available whenever
contacting or corresponding with your dealer or Northstar

.

If
you need help, call the Northstar Service Department at
978-897-6600.

NOTE:

To prevent delays, it’s critical that you first obtain a Return Materials
Authorization (RMA) number from the Service Department before return­ing your 958 to Northstar.

The 958 is covered by a two-year limited warranty (see the
Limited Warranty Policy at the front of this manual), which, in
summary, states that if the 958 is returned to Northstar by the
owner or dealer during the warranty period, Northstar will

Page 4 958 Operator’s Manual, Rev. A

repair or replace, free of charge, any part found to be defective
due to faulty materials or workmanship, if the 958 has been
properly installed and hasn’t been abused. The only cost to the
owner will be the one-way shipping charges and any
associated charges that may be imposed by the dealer.

Shipments to Northstar should be made to the following
address:

If you have special overnight or second-day shipping
requirements (UPS or Federal Express), please call Northstar
for turnaround time and freight costs before you ship your

958.

For details about service procedures, see the Limited Warranty
Policy in this manual.

Turning the 958 on and off

Chapter 1 - Getting Started

Northstar Technologies

30 Sudbury Road

Acton, MA 01720

Turning the 958 on

958 Operator’s Manual, Rev. A Page 5

To turn the 958 on, briefly press the PWR key. The 958 emits
several short beeps as it displays the START-UP screen, then
the 958 performs a series of self-tests to check its critical
components and functions.

Chapter 1 - Getting Started

After the 958 displays its START-UP and SELF-TEST screens, a
message is shown to warn you against relying on the 958’s
chart cartography as the only means of safe navigation.

CAUTION!

Be extremely careful when navigating with electronic
charts. Although every effort has been made to ensure that the

data the 958 uses is as close as possible to paper charts,
errors and omissions are inevitable. The captain is responsible
for cross-checking the 958 against other sources of navigation
data.

To continue, accept the WARNING MESSAGE by pressing any
one of the five function keys (CHART, STAR, STEER, NAV
LOG, or WAYPTS/ROUTES) located below the display screen.
A 958 that has recently been used at or near that same loca­tion will usually be ready to navigate within one minute.

Now you’re ready to get underway with your 958!

Page 6 958 Operator’s Manual, Rev. A

Chapter 1 - Getting Started

Checking GPS and

WAAS status

Turning the radar

on

Turning the 958 off

Once the 958 is on and has acquired its satellite data, you can
always check the quality of the GPS signals by viewing the
various satellites’ SNR reading (Signal-to-Noise Ratio) as
described in see ”Viewing GPS satellite status” starting on page

62.

If you have radar installed and connected to Port 2, it won’t be
operational until you turn on the radar transmitter. See
”Turning radar on and off” beginning on page 128.

To turn the 958 off, press and hold the PWR key for a few
seconds until the screen goes dark.

Displaying the chart screen

Displaying your

vessel’s present

position

After the 958 successfully completes its start-up sequence,
press the CHART function key to display the CHART screen.
You’ll see your present position represented by a black
triangular vessel symbol in the center of the chart. The DGPS
or WAAS indicator on the right side of the screen means the
958 is currently receiving radiobeacon (optional) or WAAS
signals. White areas are water and brown areas are land. If
you’re using a chart cartridge, nav aids and depth contours are
shown as well as landmark names.

958 Operator’s Manual, Rev. A Page 7

Chapter 1 - Getting Started

If your vessel is moving, the symbol will point in the direction
of your course over ground. This direction may be different
from your heading. The vessel symbol shows your actual
direction of travel over the bottom, not the direction you’re
headed. If your vessel isn’t moving, the 958 can’t determine
your COG, so the direction of the vessel symbol won’t mean
anything.

The scale of your first view is about 128 nautical miles (nm)
from edge to edge. To see more details about your position,
press the IN key. To see more area and less detail, press the
OUT key.

Rotating the chart

Displaying other

information

Clearing a GPS or

WAAS alarm

To change the chart-viewing angle from north-up to course-up
to heading-up to leg-up, cycle through the choices by pressing
the ROTATE key. The current angle is shown at the bottom
half of the key.

You can set up your 958’s CHART screen to display your
current route, your track history, nearby waypoints or
avoidance points, a lat/lon grid, a radar overlay, or other chart
details. For details, see see ”Setting up the chart screen”
starting on page 53.

If the 958 doesn’t acquire GPS or WAAS signals within two
minutes, you’ll see a flashing NO GPS alarm icon on the lower
right side of the screen. This means the 958 has an alarm
message that needs your acknowledgement: Press the STAR
function key (twice if the echo sounder is installed) to display
the ALARMS screen.

Page 8 958 Operator’s Manual, Rev. A

Chapter 1 - Getting Started

The alarm message NO GPS POSITION FIX is shown in the
RECENT ALARMS box. This message is a normal part of using a

958 for the first time, and advises you that the 958 is acquiring
the necessary satellite information. This situation usually
occurs in a 958 that’s been shipped more than several
hundred miles from Northstar, and often just the first time the
958 is turned on. This first time, the 958 takes two to five
minutes to acquire the necessary information, and after that, is
ready to navigate.

The word NEW in the upper right corner tells you this message
hasn’t already been acknowledged. To acknowledge, press the
CLEAR ALARM menu key. As soon as the 958 acquires its
signals, you’ll be ready to go.

For details about alarms, see ”Using the alarms” starting on
page 25, and see ”Understanding alarms” starting on page 144.

Using chart data

You have two choices for viewing chart data:

•

use the 958’s built-in Navionics worldwide maps

•

use Navionics’ chart-data cartridges

The 958
entire world at a fairly low level of detail. This large-scale set of

958 Operator’s Manual, Rev. A Page 9

contains a built-in, low-resolution map that covers the

Chapter 1 - Getting Started

maps can give you an approximate idea of your location with
respect to land areas. Nav aids are not included.

For more detailed charting data, you’ll want to use Navionics’
highly detailed miniature Nav-Chart™ cartridges. Navionics is
a major producer of high-quality, high-resolution “seamless”
digital charts. The 958’s usefulness is greatly enhanced with
cartridges for the areas to which you plan to navigate.
Cartridge data is the result of countless hours of converting
land-mass shapes, nav-aid names and locations, depth
contours and other information found on official paper charts
into an electronic format used by the 958. Each cartridge
includes several charts covering a specific geographic location,
typically providing zoom in and out levels ranging from a
maximum detail of 1/4 nm across the screen to an overview of
up to 256 nm across. Virtually every major port and most
popular boating areas are available on these cartridges, and
new charts are constantly being added. For details about
obtaining Navionics charts, contact your authorized Northstar
dealer.

Inserting a chart

cartridge

Page 10 958 Operator’s Manual, Rev. A

The cartridge slot is located at the lower left-hand corner of
the 958. You can see if a cartridge is inside by opening the
cartridge access door and looking inside the slot. If the 958 is
on, press the CHART SETUP menu key to the right of the
CHART screen to display the CHART STATUS screen (the
cartridge door must be fully closed and latched to display this
information):

•

If a cartridge is inside, the cartridge name and date are
shown at the left of the CHART SETUP/STATUS screen
(screen at left, below).

Chapter 1 - Getting Started

•

If a cartridge isn’t installed or is installed incorrectly, the
words NONE INSERTED are shown (screen at right, below).

NONE

INSERTED

The cartridge name comes from its Navionics catalog number.
Not all cartridges will have a date, especially older ones; in this
case, only the word PRESENT is shown rather than the name
and date.

Before you insert the cartridge, make sure the cartridge label is
facing up and the cartridge is oriented as shown in Figure 1:
”Properly inserting a chart cartridge,” below. Insert the
cartridge gently but firmly into position with one straight,
smooth motion. If you only partially insert the cartridge, stop,
then move the cartridge again, it may get stuck in an awkward
position.

958 Operator’s Manual, Rev. A Page 11

Chapter 1 - Getting Started

The Navionics chart cartridge
must remain free from debris
and moisture at all times. To
ensure that you do not expose
the cartridge to any environ­mental damage, please use
caution when changing the
cartridge. Be careful when
inserting the cartridge into the
958 (see description and illus­tration at right). When you’re
not using the cartridge, store it
in a clean, dry place away
from heat, humidity, and dust.
Improper handling and stor­age of the cartridge may dam­age the Northstar 958. Such
damage is not covered under
the 958 warranty.

Figure 1: Properly inserting a chart cartridge

Page 12 958 Operator’s Manual, Rev. A

Displaying detailed position information

You can display detailed position information on two screens:

•

the CHART screen

•

the GPS POSITION screen

To display position information on the CHART screen, press
the MORE INFO menu key to display an “info bar” at the
bottom of the screen.

Chapter 1 - Getting Started

Each additional press of the MORE INFO key shows the
following information:

•

your vessel’s present Speed-Over-Ground (SOG),
Course-Over-Ground (COG), and heading

•

your vessel’s distance (DIST) and bearing (BRG) to the cur­rent waypoint, if any

•

your vessel’s position in lat/lon (or TDs, if enabled)

•

the depth, water temperature, and Speed-Through-Water
(STW) as measured by the echo sounder

To display position information on the GPS POSITION screen,
press the CHART function key again to display the GPS
POSITION screen.

958 Operator’s Manual, Rev. A Page 13

Chapter 1 - Getting Started

The GPS POSITION screen shows the following information:

•

your vessel’s position in lat/lon (or TDs, if enabled)

•

your vessel’s present SOG and COG

•

current time, day, and date

•

geodetic datum (for details, see ”Appendix C - Geodetic
Datums” starting on page 197)

For details about determining and displaying your position,
see ”Determining Your Position” starting on page 59.

Using demo mode

You can use demo mode to simulate a stationary position, or
simulate going to a cursor location on the CHART screen.

To access demo mode, on the CHART screen, press the CHART
SETUP key, then press the DEMO CONTROL key to display
the DEMO CHART screen.

Page 14 958 Operator’s Manual, Rev. A

Chapter 1 - Getting Started

To move your vessel to a simulated position, press the
CURSOR PAD to move the cursor to the desired position and
press the DEMO POSITION key. To start demo mode at this
new position, press the ENTER key. Your vessel symbol will
now be stationary at this position.

To travel from here to a new cursor location, press the
CURSOR PAD to move the cursor to the desired position, then
press the DEMO COG/SOG key. To set your vessel’s speed, use
the KEYPAD to enter the desired speed, then press the ENTER
key to start going to the demo cursor location.

To go back to the CHART screen (but stay in demo mode),
press the RETURN key twice. The word DEMO always appears
on the CHART screen when you’re in demo mode.

To exit demo mode, on the DEMO CHART screen, press the
EXIT DEMO key. This immediately returns you to the CHART
screen.

NOTE:

Video image display, simulated radar image, chart rotation, and zooming
in and out all work normally on the

DEMO CHART

screen.

958 Operator’s Manual, Rev. A Page 15

Chapter 1 - Getting Started

Going to a quick waypoint now

You can point to any location on the CHART screen and go
right to it. This is called “point-and-shoot” navigation, which
can be the easiest and most powerful way to go to a waypoint:
Just select different locations and go to them, one at a time,
right on the chart. This way of navigating provides the most
flexibility in deciding where you want to travel. Simply move
the cursor wherever you want, press a key, and you’re
navigating.

1. Press the CHART function key to display the CHART
screen.

2. Move the cursor to the desired chart location by pressing
the CURSOR PAD in the lower right corner of the 958.

3. Press the GO TO CURSOR menu key at the lower right of
the screen.

4. When prompted with the message START NAVIGATING
TO CURSOR POSITION, press the ENTER key.

Page 16 958 Operator’s Manual, Rev. A

Chapter 1 - Getting Started

The 958 displays a track line to the new waypoint named

-QUIK-, and guides you directly to this point.

That’s all you have to do to use the 958 in its simplest
form. To learn more about navigating to waypoints, see
”Navigating to waypoints” starting on page 110.

958 Operator’s Manual, Rev. A Page 17

Chapter 1 - Getting Started

Page 18 958 Operator’s Manual, Rev. A

2

Introducing the 958

Introducing the controls . . . . . . . . . . . . . . . . . . . . 20

Introducing the display screen . . . . . . . . . . . . . . 21

Introducing radar . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Introducing the echo sounder . . . . . . . . . . . . . . 25

Introducing alarms, TideTrack, and video . . . 25

Maintaining the 958 . . . . . . . . . . . . . . . . . . . . . . . . 26

Interfacing the 958 . . . . . . . . . . . . . . . . . . . . . . . . . 28

his chapter introduces you to the 958’s features, functions,

T

and display modes.

958 Operator’s Manual, Rev. A Page 19

Chapter 2 - Introducing the 958

Introducing the controls

Figure 2 below illustrates the functions of the 958’s controls.

Feel free to try any of the 958’s controls! You can’t hurt
anything, and can only learn more about how to use the 958
more efficiently. The 958 always asks you to verify what
you’re doing when changing or deleting information. You’ll be
asked to confirm your action before anything happens that
may affect the 958’s operation. You can always cancel a
function at the last second.

For details about each of these controls, see ”Using the
Controls” starting on page 29.

NORTHSTAR
957

Figure 2: 958 controls

Page 20 958 Operator’s Manual, Rev. A

Introducing the display screen

Chapter 2 - Introducing the 958

Overhead view

Chart screen redraw

feature

Split screen/overlay

feature

The 958’s CHART screen displays navigation data in an easily
recognizable, practical format: an overhead view of your
vessel’s present position (or any position you choose) in
relation to land masses, nav aids, and your own defined
waypoints and routes. As you navigate, your vessel remains
centered on the CHART screen, and the chart moves
underneath your vessel.

The CHART screen’s high-speed redraw feature means you
don’t have to wait when you’re scrolling from one location to
the next. The 958 automatically keeps the chart visible—even
as you move from one chart to the next. Move the cursor,
press a key, and you’re still navigating through a channel,
around an island, or in open water—always in full view of
what’s around you at all times.

Occasionally, you may see an hourglass symbol briefly
displayed on the screen while the 958 is changing or
redrawing the chart.

If your 958 is equipped with radar and/or echo sounder, you
can split the screen to show the chart, radar, and sounder
together in various combinations. In addition, you can overlay
a radar image on the chart and/or overlay a video image on
most screens. An introduction to these functions is given later
in this chapter. For details about the split screen, see ”Splitting
the screen” starting on page 46.

Display-screen

lighting

958 Operator’s Manual, Rev. A Page 21

The 958’s large full-color screen is easily readable under all
conditions from full, direct sunlight to total darkness.
Anti-reflection treatment of the display and its window
eliminates over 90 percent of the reflection and glare usually
encountered in bright sunlight.

Chapter 2 - Introducing the 958

Adjusting the brightness

The fluorescent tubes that illuminate the 958 slowly dim after
several thousand hours of use. If you use your 958 for many
hours each day, you may want to keep the level of the display
lighting low when you don’t really need it. To adjust the
screen’s brightness, press the BRIGHTNESS key: Pressing the
upper arrow brightens the screen; pressing the lower arrow
darkens it.

Chart plotter

function

Auto-dimming

The 958 plots your position on the CHART screen. Nearby land
masses, depth contours, nav aids, waypoints, avoidance areas,
and a lat/lon grid may be displayed, along with your vessel’s
image. When you’re using the 958 as a chart plotter, the menu
keys to the right of the display screen let you perform the
following functions:

•

restart the desired track line to run directly from your
position to the waypoint, “zeroing” the cross-track error
display

•

change the options available for the CHART screen

•

display additional position information in the INFO BAR at
the bottom of the screen

•

go to a waypoint, nav aid, or unmarked point you select
on the CHART screen by pressing the CURSOR PAD

When the display screen is at full brightness, if the 958
becomes too hot inside due to the outside temperature and
sunlight, the display screen will automatically dim.
Auto-dimming helps maintain the integrity of the display and
reduce power consumption when the 958 is on and running
too hot for its current environment. You can override the
auto-dim function at any time by increasing the brightness
with the BRIGHTNESS key. The 958 may dim again as
required so as not to exceed the maximum internal
temperature.

Page 22 958 Operator’s Manual, Rev. A

Chapter 2 - Introducing the 958

Special display

windows

Occasionally, the 958 needs to tell you something or ask
permission to do something. When this happens, a special
information or question window appears on the display. This
window may contain an alarm icon, or an INFO label or a large
question mark along with a message for you to read.

Flashing alarm icons

The 958 communicates alarm messages by flashing an alarm
icon on the bottom right side of the screen. Alarm messages
contain information you may want to read as soon as possible.
To see the alarm condition on the ALARMS screen, press the
STAR function key (twice if the echo sounder is enabled).
Messages you haven’t seen already display the word NEW in
the upper right corner. To turn off the flashing icon and
remove the message, press the CLEAR ALARM menu key.

Info windows

The 958 displays info windows while you’re entering data or
using control functions. These windows give extra details
about what’s going to happen, or let you acknowledge a
command. Info windows always appear with the word INFO in
a small box.

958 Operator’s Manual, Rev. A Page 23

Chapter 2 - Introducing the 958

Question windows

A question window appears when the 958 needs a response
from you. You must respond to any question window by
pressing the ENTER key to answer yes, or the CLEAR key to
answer no. Most of the other keys, including the function keys
as well as the video image display, are temporarily inactive
while the 958 displays a question window.

Page 24 958 Operator’s Manual, Rev. A

Introducing radar

With radar, you can determine where other boats or ships,
navigational markers, land masses, flocks of birds, and other
objects are located in relation to your vessel, and you can track
their movements.

You can display radar by itself or in combination with the
chart and sounder. You can also overlay the radar image on
the CHART screen. For details about radar functions, see
”Understanding Radar Functions” starting on page 125.

For information about the radar setup, see ”Setting up radar”
starting on page 177. For information on installing radar and
making it operational, see the Northstar Radar Installation
Manual (part number GMRadarIM).

Introducing the echo sounder

If your 958 is equipped with Northstar’s optional sounder,
pressing the STAR key will display the full ECHO SOUNDER
screen. You can also display the ECHO SOUNDER screen in
various combinations with other screens.

For information about viewing the sounder in combination
with other screens, see ”Splitting the screen” starting on page

46. For information about the sounder setup, see ”Setting up
the sounder” starting on page 177. For details about using (and
installing) the sounder, see the Northstar 490 Operator’s
Manual (part number GM490).

Chapter 2 - Introducing the 958

Introducing alarms, TideTrack, and video

The 958 has several special functions:

•

alarms

•

TideTrack display

•

video image display

Using the alarms

958 Operator’s Manual, Rev. A Page 25

The 958 has several alarms that automatically alert you to
certain situations. For example, when you’re approaching a
waypoint, the 958 lets you know by sounding a beep and

Chapter 2 - Introducing the 958

flashing an alarm icon on the screen. The 958 offers four
adjustable alarms, including anchor, cross-track distance,
arrival radius, and DGPS time-out. For details, see
”Understanding alarms” starting on page 144.

Using TideTrack™

Using the video

image overlay

The 958’s TIDE TRACK screen displays a 24-hour tide graph
for any of over 3,000 NOAA tide stations covering the entire
U.S. coastline, including Alaska and Hawaii, plus much of the
eastern and western Canadian coastline. You can display tides
for the current date or any other date. For details about
TideTrack, see ”Understanding TideTrack™” starting on page

158.

The 958 offers a video display feature that lets you overlay an
image from a connected video source onto most of the 958’s
display screens. You can also easily adjust the size, position,
and transparency of the image (that is, how much of the
underlying screen you can see through the video image). For
details, see ”Using the video display option” starting on page

160.

Maintaining the 958

Basic maintenance

To help retain the 958’s best possible performance, Northstar
recommends following these suggestions:

•

•

•

•

•

keep the cartridge access door closed at all times, unless
inserting or removing a chart cartridge, to prevent
moisture and dirt from entering the 958

don’t change the cartridge when the 958 is exposed to
water spray, rain, or moisture of any kind

keep spare cartridges in a safe, watertight place where
they can’t be misplaced

keep fingerprints off the display screen (remove any prints
with a lens cleaning cloth)

remove dirt and grime with Windex and a soft cloth, or
else soap and water

Page 26 958 Operator’s Manual, Rev. A

Chapter 2 - Introducing the 958

•

don’t scratch the display by scraping a sandy or salty cloth
across it

•

use the 958’s protective plastic cover when not in use

•

don’t open the 958’s case—there aren’t any
user-serviceable parts inside

Cleaning the display

screen

Pre-packaged moist tow­ellettes (especially those
containing a small amount
of alcohol) are excellent for
cleaning the 958’s display
window. You might want to
keep a supply on hand to
wipe off fingerprints and
other smudges.

Protecting the 958

Be careful when cleaning the glass window covering the
display screen. Although the window is scratch-resistant, you
may damage the anti-reflective coating if you use a dry cloth
to wipe dirt off. When wiping the window, always use a damp
cloth or a clean and dry microfiber-type lens cleaning cloth. To
dissolve any oil or grease on the screen, use a small amount of
window cleaner or alcohol.

If possible, try not to touch the window with your fingers. The
natural oils from your hand will temporarily affect the
characteristics of the screen and cause your fingerprints to
appear as bright reflections. These will disappear, however,
when you clean the screen as described above.

Excessive heat can cause short- and long-term damage to the

958. Although the 958 can recover from short-term effects,
long-term damage may be permanent. When the 958 is out in
the hot sun, but isn’t being used, always use the protective
plastic cover.

If left disconnected and exposed, the 958’s rear connectors
may corrode slightly from exposure to saltwater spray. If the
connectors are not in use, always keep their plastic caps on.

Protect the entire 958 from prolonged exposure to the
elements by mounting it, if possible, in a relatively dry
location. At the end of a trip, wipe the 958 dry.

958 Operator’s Manual, Rev. A Page 27

Chapter 2 - Introducing the 958

Interfacing the 958

The 958 can be connected to a wide variety of compatible
marine devices, including the Northstar 490 that adds
complete fishfinding capability to the 958. This type of
connection should be done by a qualified marine electronics
technician. For details, contact your local authorized Northstar
dealer.

Page 28 958 Operator’s Manual, Rev. A

3

T

operate the 958.

Using the Controls

Using the PWR key . . . . . . . . . . . . . . . . . . . . . . . . . 30

Using the five function keys . . . . . . . . . . . . . . . . 30

Using the CURSOR PAD . . . . . . . . . . . . . . . . . . . . . 32

Using the SAVE key . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the MOB key . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the alphanumeric KEYPAD . . . . . . . . . . . 34

Using the menu keys . . . . . . . . . . . . . . . . . . . . . . . 35

Using the BRIGHTNESS key . . . . . . . . . . . . . . . . . 36

Using the IN and OUT keys . . . . . . . . . . . . . . . . . 36

his chapter explains how to use all of the various controls to

958 Operator’s Manual, Rev. A Page 29

Chapter 3 - Using the Controls

Using the PWR key

To turn the 958 on, briefly press the PWR key. The 958 emits
several short beeps as it first displays the STARTUP screen,
followed by the SELF-TEST screen. This screen displays the
results of the 958’s self-tests, which are automatically run each
time you turn power on. After you clear the WARNING
MESSAGE, the 958 will display navigational data.

To turn the 958 off, press and hold the PWR key for several
seconds until the screen goes dark.

Using the five function keys

The five function keys—CHART, STEER, WAYPTS/ROUTES,
STAR, and NAV LOG—located across the lower left part of the

958, control the functions you’ll use most often. You can press
any function key, at any time, on any screen, to display the
information you need.

CHART function key

“Where am

I?”

STEER function key

“How do I get

to my

waypoint?”

Page 30 958 Operator’s Manual, Rev. A

The CHART key displays your position on the CHART screen
(shows lat/lon graphically) or on the GPS POSITION screen
(shows lat/lon numerically). Both screens also display COG
and SOG.

You can display position as any of the following:

>

as GPS/WAAS or DGPS lat/lon coordinates

>

as lat/lon from an external loran receiver (if connected)

>

as loran TDs (if you’ve connected a loran to the 958)

>

as Phantom Loran TDs (by converting GPS coordinates
to Loran TD’s)

The STEER key shows you how to steer precisely along a
course line to a designated waypoint. Your position is shown
in relation to your course line, and numerical information is
shown to help you steer directly to your waypoint, including
cross track error, distance and bearing, estimated time to
waypoint, estimated time of arrival, COG and SOG, and speed
of advance.

Chapter 3 - Using the Controls

There are two versions of the steer display: traditional
STEERING and 3D STEER. Press the STEER function key once
to see the version you last used. Press it again to see the other
one.

For details, see ”Steering to a waypoint” starting on page 112.

STAR function key

The STAR key lets you:

•

display the optional ECHO SOUNDER screen (this requires
the optional Northstar echo sounder; see the Northstar
490 Operator’s Manual, part number GM490, for details
on sounder setup and operations)

•

display an explanation of alarms and any messages the
958 has for you, and set the alarms that are adjustable

•

display the VIDEO SETUP screen, where you enable the
video image and adjust its size and placement on the dis­play screen

•

display graphical TideTrack information at over 3,000
NOAA tide stations

•

display the time, day, and date, and the time of today’s
sunrise and sunset

•

display screens that lets you set up the 958 according to
your specific needs

For details about alarms, TideTrack, and video, see ”Alarms,
TideTrack, and Video Display” starting on page 143. For details
about setting up your 958, see ”Setting Up Your 958” starting
on page 163.

WAYPTS/ROUTES

function key

“Where do I

want to go?”

958 Operator’s Manual, Rev. A Page 31

The WAYPTS/ROUTES key lets you:

•

create new waypoints and routes

•

display a list of previously stored waypoints and routes

•

choose where you want to navigate

For details, see ”Understanding the Waypoints Function”
starting on page 71, and see ”Understanding the Routes
Function” starting on page 93.

Chapter 3 - Using the Controls

NAV LOG function

key

“How am I

doing?”

The NAV LOG key displays a list of the waypoints you’ve
passed, lets you change those ahead of you, reverse the
direction of your trip, and stop or restart navigation. For
details, see ”Using the Nav Log” starting on page 121.

Using the CURSOR PAD

Pressing the large CURSOR PAD — located in the lower right
corner of the 958 — while you’re displaying the CHART screen
will move the cursor across the CHART screen in an up and
down, left to right, or diagonal direction. To move the cursor
diagonally, press the CURSOR PAD between any two of its
arrows.

Pressing the CURSOR PAD while displaying text screens will
move the flashing cursor to the data you want to either display
or change. For example, when you’re entering such data as the
name of a waypoint, or its coordinates, press the CURSOR
PAD down to move the cursor down to a particular area of
data, then press the CURSOR PAD right to move the cursor to
a particular character in that area.

The cursor itself may be hard to see when it’s located in a busy
section of the CHART screen. To help you, the 958 displays
four small red cursor pointers in the middle of each side of the
screen (see below) that match and follow the cursor’s position.
You can always rely on these pointers to show you the cursor.

Page 32 958 Operator’s Manual, Rev. A

Cursor pointers

Using the SAVE key

The SAVE key instantly saves your vessel’s position as a
waypoint—at any time, on any screen, during any function.
Press the SAVE key to store your position. This new waypoint
is automatically given a name, such as -S001-, where the letter
S indicates a saved waypoint and the three-digit number
increases by one (-S002-, -S003-, etc.) every time you save a
new waypoint this way. Three-digit numbering of waypoints
will restart at -S001-, which means the 958 will start to
overwrite the existing numbered waypoints, as soon as the 958
reaches the maximum number of saved waypoints you’ve set.
For details about using the MAX SAVED WAYPT # function in
the DISPLAY OPTIONS menu, see ”Choosing the number of
saved waypoints” starting on page 166.

Chapter 3 - Using the Controls

Using the MOB key

To enter Man Overboard mode (MOB), press the MOB key to
display the MAN OVERBOARD info window. The 958 will save
your position and display it on the CHART screen as a
waypoint with the name –MOB– and the dot waypoint symbol.
The zoom level will be set automatically to the maximum
detail of 1/4 nm range. The CHART screen locks, showing your
vessel’s position and the MOB location. The MOB location has

958 Operator’s Manual, Rev. A Page 33

Chapter 3 - Using the Controls

immediately become your current waypoint, with new
distance and bearing information displayed on the right side
of the screen.

INVOKING MOB WHILE USING AN AUTOPILOT

Some autopilots try to steer your vessel according to any
bearing changes output by the 958, regardless of the severity
of the change. Others automatically disengage when a severe
or abrupt turn is required. For details about this procedure,
check your autopilot manual.

To leave MOB mode and return to normal navigation, press
the MOB key until the 958 displays the BACK TO NORMAL —

MOB TURNED OFF message. Notice that the waypoint named

-MOB- is still stored.

Using the alphanumeric KEYPAD

The 12-key alphanumeric KEYPAD is used to enter numbers,
letters, or special characters for waypoint coordinates, names,
and similar functions.

CAUTION!

Entering numbers

Page 34 958 Operator’s Manual, Rev. A

When the 958 expects you to enter only numbers, such as
waypoint coordinates, you can use the KEYPAD to enter one
digit (0 through 9) with each keypress. The flashing cursor
moves automatically to the next digit position.

For entries such as latitude and longitude—where you must
enter digits into specific character positions—the cursor starts
on the left side of the data area, and you enter characters left
to right into their correct positions.

For other numeric entries such as distances—where you can
enter numbers of different lengths—you enter the digits

Chapter 3 - Using the Controls

calculator-style from the right side of the data area. If you
make a mistake, press the CLEAR key to clear the entire
number and re-enter it, or press the CURSOR PAD left to
re-enter particular digits one at a time.

Entering letters and

characters

Using the CLEAR

and ENTER keys

When the 958 expects you to enter letters, such as waypoint
names and descriptions, the operation is slightly different than
entering numbers. Each key is labeled with three letters and a
digit. For example, the upper left key is labeled with the letters

A, B, C and the digit 1. Press this key once to display the letter
A. Press this key again to display the second letter, B. Pressing

a third and fourth time displays the letter C and the digit 1,
respectively. A fifth press brings you back to the letter A again.

To enter a character, first find the key containing the
character, and press that key one to four times to display the
desired character. To move the cursor to the next character
position, press the CURSOR PAD right.

The KEYPAD has CLEAR and ENTER keys for erasing or
entering data that’s already been typed. The CLEAR key
removes any data you’ve already typed—resetting the field to
all blanks or restoring the original value. The ENTER key is
always the last step when entering or changing data, or when
acknowledging an action.

The CLEAR and ENTER keys are also used to reject or accept
actions displayed in question boxes that appear on the screen.
For example, if you press the GO TO CURSOR key, the 958
displays the message START NAVIGATING TO CURSOR
POSITION? YES... PRESS “ENTER” NO... PRESS “CLEAR,” and
waits for you to press the ENTER or CLEAR key.

Using the menu keys

The six round MENU keys on the right side of the screen have
a variety of functions that usually depend on the screen you’re
currently displaying.

958 Operator’s Manual, Rev. A Page 35

Chapter 3 - Using the Controls

Using the BRIGHTNESS key

To get the best picture for the current conditions, the 958’s
screen may require minor adjusting for different viewing
angles, temperature conditions, etc. Press the BRIGHTNESS
key (the unlabelled double arrow) to adjust the screen’s
brightness.

Using the IN and OUT keys

On the CHART and the 3D STEER screens and on the radar,
each press of the IN key zooms in to double the scale, and each
press of the OUT key zooms out to halve the scale.

On other screens, you can also use the IN key and OUT keys to
adjust the transparency of the video image, if already
displayed: Pressing IN lets you see more of the video image,
and pressing OUT lets you see more of the screen underneath
the image.

Page 36 958 Operator’s Manual, Rev. A

4

T

modes (vessel and browse), the various chart symbols and
their meanings, and how to set up the chart display.

Using the Chart Screen

Understanding electronic charts . . . . . . . . . . . . 38

Understanding nav aids . . . . . . . . . . . . . . . . . . . . 39

Zooming in and out . . . . . . . . . . . . . . . . . . . . . . . . . 41

Controlling the cursor on the chart screen . . 42

Comparing vessel and browse modes . . . . . . . 44

Splitting the screen . . . . . . . . . . . . . . . . . . . . . . . . . 46

Controlling the screen . . . . . . . . . . . . . . . . . . . . . . 48

Rotating the chart . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Setting up the chart screen . . . . . . . . . . . . . . . . . 53

Using distance and bearing mode . . . . . . . . . . . 57

his chapter explains the electronic chart, the different chart

958 Operator’s Manual, Rev. A Page 37

Chapter 4 - Using the Chart Screen

Understanding electronic charts

Each Navionics chart cartridge contains electronic chart data
from several paper charts. Electronic charts have much of the
information from the original paper charts, although spot
depth soundings, some nav aids, and other data may be
missing. When used with caution, electronic charts open up a
world of navigational accuracy and simplicity.

Don’t become overly confident when using electronic charts.
Always be cautious!

CAUTION!

Chart boundary

lines

Chart details

The 958 displays the boundary line of each chart on the

CHART screen. To turn this feature off, press the CHART
SETUP key on the CHART screen, then press the CHART
DETAIL key and turn off the CHART EDGES option.

If you move from a highly detailed chart to a less detailed one,
you may see a sudden change in the detail shown on the
screen, just as if you had changed from one detailed paper
chart to a less detailed one. You may be able to use the
displayed boundary lines to predict when this change in detail
is going to happen.

Page 38 958 Operator’s Manual, Rev. A

Understanding nav aids

The nav aids on the CHART screen represent a variety of
standard “aids to navigation” used on coastal and inland
waterways throughout the United States. Nav aids are
displayed on the CHART screen as colored circles with white
letters. Most of these aids comprise buoys, lights, lighthouses,
and daybeacons, which typically are maintained by the U.S.
Coast Guard. Nav aids warn you of hidden dangers, such as
underwater hazards, and to help you to safely navigate specific
waterways and channels.

Nav aids have been converted from official paper charts into
the electronic format on your screen, and therefore aren’t
necessarily as accurate as the paper charts. You can expect
about a 95 percent accuracy rate. In some areas, only the most
important nav aids may be shown.

Chapter 4 - Using the Chart Screen

CAUTION!

Buoys

958 Operator’s Manual, Rev. A Page 39

Buoys are the most common type of nav aid. The 958 shows
green and red channel markers as green and red circles,
respectively.

Approach buoys are shown as circles with black on the upper
half and white on the lower half.

Sound buoys (featuring an audible signal, such as a bell, gong,
or whistle) are identified by a description in the INFO BAR
such as BELL, WHIS, GONG, or HORN).

Some nav aids have no chart symbol, and are shown on the
CHART screen as text only.

When you move the cursor onto a nav aid, the 958 displays a
description in the INFO BAR at the bottom of the screen, along
with the distance and bearing from your vessel to the nav aid.

Chapter 4 - Using the Chart Screen

Landmarks

There are other objects shown on the CHART screen that
aren’t classified as nav aids, including various onshore
landmarks.

Page 40 958 Operator’s Manual, Rev. A

Zooming in and out

To get a closer look at the chart area around your vessel or
around the cursor, press the IN key to zoom in. To see a wider
area, press the OUT key to zoom out. Each press of the IN or
OUT key approximately halves or doubles the chart scale,
respectively.

At the highest detail for a particular chart, you can use the 958
as a precision plotter. When you zoom in past that level, the
center of the chart is magnified to fill the screen and all text
and symbols are doubled in size. Zooming in still further
causes the 958 to remove all chart detail from the screen for
safety reasons, leaving only your vessel, its track, user-entered
waypoints, and the lat/lon grid.

Chapter 4 - Using the Chart Screen

958 Operator’s Manual, Rev. A Page 41

Chapter 4 - Using the Chart Screen

As a reminder that no charted hazards or nav aids are shown,
the 958 displays the words NO CHART multiple times across
the screen. Even without any chart data displayed, you can
still use the 958 as a precision plotter

If the chart has a radar overlay and if you change the chart’s scale (by
zooming in or out), the scale of radar changes to match. If you change the
scale of radar, the scale of the chart also changes to match, even if the
chart isn’t visible at the time. However, if the radar overlay doesn’t appear
on the chart, you can scale the chart and radar separately.

NOTE:

Controlling the cursor on the chart screen

Pressing the CURSOR PAD displays the cursor symbol on the
CHART screen. Further pressing of the CURSOR PAD will
move the cursor across the screen. If you have trouble finding
the cursor in a busy part of the CHART screen, just look at the
sides of the screen for the red cursor pointers: They match up
with the cursor.

If you move the cursor right onto an object, such as a
displayed waypoint, you will select that object, as indicated by
a diamond-shaped box (see left) around the object.
Information about the selected object appears at the bottom of
the screen, as shown below.

Page 42 958 Operator’s Manual, Rev. A

Chapter 4 - Using the Chart Screen

After pressing the CURSOR PAD to scroll around on the chart,
you can press the GO TO CURSOR menu key to start
navigating to the designated cursor location. If you place the
cursor on a waypoint or nav aid, this menu key would be GO
TO WAYPT or GO TO NAV AID, respectively.

You can use the cursor for the following functions:

•

select a nav aid or waypoint, to:

>

show its name, lat/lon, and distance and bearing

>

navigate to it

>

add it to a route

•

designate a point on the chart, to:

>

show its lat/lon

>

navigate to it

>

add it to a route

>

store as a waypoint

•

select a leg of a route to follow or edit

•

view a new area of the chart by moving the cursor to the
edge of the chart

958 Operator’s Manual, Rev. A Page 43

Chapter 4 - Using the Chart Screen

Comparing vessel and browse modes

The 958 offers two display modes:

•

vessel

•

browse

As long as the CONTROL key shows (CHART), Pressing the
CURSOR PAD at any time instantly changes the display from
vessel mode to browse mode. When you’re in browse mode,
pressing the VESSEL menu key at any time instantly displays
your vessel in the center of the CHART screen, returning the
958 to vessel mode.

Vessel mode

Vessel mode is indicated by the word VESSEL in the upper
right corner of the screen. In this mode, you can perform the
following functions:

•

see your vessel’s present position in relation to your
intended course line and any nearby waypoints, nav aids,
land masses, etc.

•

split the screen (SPLIT key) to display the chart
simultaneously with radar and/or the optional sounder
screen and/or a video image; for details, see ”Splitting the
screen” starting on page 46

•

control the chart (CONTROL key); for details, see
”Controlling the screen” starting on page 48

Page 44 958 Operator’s Manual, Rev. A

Chapter 4 - Using the Chart Screen

•

rotate the chart (ROTATE key); for details, see ”Rotating
the chart” starting on page 49

•

restart your course line from your present position to
your intended waypoint (RESTART key); for details, see
”Restarting navigation” starting on page 124

•

display or change the setup functions for the CHART
screen (CHART SETUP key); for details, see ”Setting up
the chart screen” starting on page 53

•

display position details at the bottom of the screen (MORE
INFO key)

Browse mode

Browse mode is indicated by the word BROWSE in the upper
right corner of the screen. In this mode, you can perform the
following functions:

•

view any area on the chart by moving the cursor there
(CURSOR PAD)

•

quickly determine distance and bearing to other points on
the CHART screen (CURSOR PAD)

•

split the screen (SPLIT key) to display the chart
simultaneously with radar and/or the optional sounder
screen and/or a video image; for details, see ”Splitting the
screen” starting on page 46

•

control the chart (CONTROL key); for details, see
”Controlling the screen” starting on page 48

958 Operator’s Manual, Rev. A Page 45

Chapter 4 - Using the Chart Screen

Splitting the screen

If you have radar and/or the echo sounder installed and
operational, you’ll see the SPLIT key when you view the
CHART screen; otherwise, you’ll see a VIDEO key. The
following discussion assumes that the SPLIT key is available.

You can split the screen in the following ways:

•

rotate the chart (ROTATE key); for details, see ”Rotating
the chart” starting on page 49

•

return to vessel mode (VESSEL key)

•

display or change the setup functions for the CHART
screen (CHART SETUP key); for details, see ”Setting up
the chart screen” starting on page 53

•

specify points to go to on the CHART screen (GO TO
CURSOR key)

•

Overlay video

•

View the chart alone

•

View the chart and sounder together

•

View the chart and radar together

•

View the chart, radar, and sounder together

•

View the radar alone

The following figure shows examples of the available screens.

Page 46 958 Operator’s Manual, Rev. A

Video
(overlaying
chart)

Chart and
sounder

Chart and
radar

Chart,
radar, and
sounder

Chapter 4 - Using the Chart Screen

Figure 3: Examples of split screens

To split the screen:

1. Press the SPLIT key to view the SELECT A SPLIT SCREEN
menu:

958 Operator’s Manual, Rev. A Page 47

Chapter 4 - Using the Chart Screen

There’s less room on a split screen than on a full screen. For detailed
viewing of the chart, sounder, or radar, choose a full screen.

You can overlay video on any screen listed on the SELECT A
SPLIT SCREEN menu by pressing the VIDEO key. For details on

the video overlay, see ”Using the video display option” starting
on page 160.

For details on the sounder, see the Northstar 490 Operator’s
Manual (part number GM490).

2. Press the key for the split you want.

NOTE:

For details on radar (and the radar overlay), see
”Understanding Radar Functions” starting on page 125.

Controlling the screen

f you have radar installed and operational, you’ll see the
CONTROL key when you view the CHART screen; otherwise,
you won’t see any key. The following discussion assumes that
the CONTROL key is available.

You are controlling the chart when the word CHART appears
on the CONTROL key.

The CONTROL key (like the ROTATE key, and several other
keys in the 958) has two parts: the upper part shows the

Page 48 958 Operator’s Manual, Rev. A

Rotating the chart

Chapter 4 - Using the Chart Screen

function of the key; the lower part (in blue) shows the current
status of the function:

Function (for example, control)

Status (for example, chart)

You press the CONTROL key once to select the key’s function
(a small arrow appears next to the function). You then press
the key again to select the key’s status (a small arrow appears
next to the status). To choose CHART or RADAR, press the key
repeatedly until it shows the status you want:

You control only one function—chart or radar—at a time.

The chart rotation feature lets you change the angle of the
charts that are displayed on the CHART screen. As long as
you’re in vessel mode, you can turn charts to any one of the
following angles:

• North up - You’ll see north pointing straight upwards (the

chart isn’t turned).

• Course-up - You’ll see your vessel’s current direction of

travel—whatever that direction is—pointing straight
upwards. Course-up represents your true COG as
determined by the GPS receiver. The 958 ignores any
course changes if your speed is under half a knot. The
chart will rotate sooner for rapid turns than for slower
ones.

NOTE:

Your COG is often different from the heading, so what you see straight
ahead in the real world may be different from what’s displayed on the
screen.

958 Operator’s Manual, Rev. A Page 49

Chapter 4 - Using the Chart Screen

If you’re viewing course-up, heading up, or leg-up, the text
from the Navionics cartridge is tilted to match the rotation
angle in order to avoid text overlap.

You can change the chart rotation right on the CHART screen
by pressing the ROTATE key.

The following three screens show how the chart looks if you’re
travelling along a sample route that has four waypoints, and
you rotate the chart from north-up to course-up and then to
leg-up.

• Heading-up - This angle is available only if you have

radar installed and enabled. Heading-up shows the radar
heading, which may not be identical to the
course-over-ground. When you select heading-up, the
heading line on the radar image points straight upwards.
The heading line allows you to compare the radar view
with the view in front of the vessel.

• Leg-up - You’ll see your vessel’s current leg to a

waypoint—whatever direction that is—pointing straight
upwards. The 958 will adjust the chart on a leg-by-leg
basis, so the chart turns accordingly whenever you start
navigating on a new leg, even if you haven’t turned the
vessel yet. Exception: If you select leg-up when you aren’t
currently navigating, the 958 automatically uses
course-up—until you start navigating along another leg.

Figure 1: North-up chart angle (first leg going northwest)

Page 50 958 Operator’s Manual, Rev. A

Chapter 4 - Using the Chart Screen

Figure 1 shows the vessel heading northwest on the first leg
from the first waypoint to the second one. The chart’s viewing
angle is set to north-up. Notice the direction of the
north-pointing arrow in the upper right corner.

Figure 2: Course-up chart angle (second leg going east)

Figure 2 shows the same chart, but with the chart’s viewing
angle now set to course-up and the vessel on a slightly
different course than the second route leg. Notice the new
direction of the north-pointing arrow.

Figure 3: Leg-up chart angle (third leg going south)

958 Operator’s Manual, Rev. A Page 51

Chapter 4 - Using the Chart Screen

Figure 3 shows the same chart, but with the chart’s viewing
angle now set to leg-up and the vessel on a different course
than the third leg. Notice the new direction of the
north-pointing arrow.

Using chart rotation

while browsing

• Course-up or Heading-up (Hdg up) - Suppose that
you’re displaying the charts as course-up or heading-up
and you press the cursor pad to go into browse mode. If
your vessel changes course, you won’t see the chart turn
to the new direction until you return to vessel mode by
pressing the VESSEL key. You must be in vessel mode to
see any changed course angle. This feature lets you keep
a steady viewing angle if you’re browsing around on the
chart.

• Leg-up - If you’re displaying charts as leg-up and the 958
switches to a new leg, you’ll see the chart rotate to the
direction of that new leg even in browse mode—unless
you’re actively pressing the CURSOR PAD.

NOTE:

If you’re displaying the charts as either leg-up or course-up, you may see
a black line with white space on the other side. This line is the edge of the
chart, which is now visible since the chart has been rotated. When the
vessel or cursor crosses the line, the display will switch to a new chart.

The edges of other charts in the 958’s built-in world atlas are shown, in
addition to those in your local cartridge. These edges are shown as black
or red dashed lines.

The lat/lon grid is labelled only when the chart is north-up.

Page 52 958 Operator’s Manual, Rev. A

Chapter 4 - Using the Chart Screen

How rotating

affects the chart and

The rotation of the chart and the rotation of the radar image
interact under certain circumstances, as described below.
Assume that the chart and radar are both north-up at the start:

radar

If the

CHART

screen’s in ...

Browse mode The chart can’t rotate; but if

Vessel mode Chart and radar both rotate

you change the
key to
mode automatically switches
to vessel (see below)

together, so if you change
the radar to leg-up, the chart
automatically changes to
match (and vice versa)

Setting up the chart screen

To set up the display of data on the CHART screen, press the

CHART SETUP menu key (in either vessel or browse mode)

And the radar image is ...

Overlaid on the chart Not overlaid

The chart can’t rotate but the
radar can rotate; so if you
change the radar to leg-up,
the chart doesn’t change (it
stays north-up)

Chart and radar both rotate
but separately; so if you
change the radar to leg-up,
the chart doesn’t change
(and vice versa)

RADAR

CONTROL

, the chart’s

On the CHART SETUP/STATUS SCREEN you can set up the
details on the CHART screen, turn the radar overlay on and off,
and adjust the 958’s track control.

958 Operator’s Manual, Rev. A Page 53

Chapter 4 - Using the Chart Screen

Choosing the chart

details

To set up the chart details, press the CHART DETAIL menu
key to display the CHART DETAIL screen.

To change any of the options, first press the CURSOR PAD to
move the cursor to the desired item, then press the ON/OFF
menu key to turn the item on or off (off is represented by two
dashes)

Lat/lon grid

The ON setting shows lat/lon lines on the CHART screen. Turn
lat/lon lines off when these lines add clutter to your screen, or
when you don’t need them.

Text i n fo

The ON setting shows the names of local cities, towns, harbors,
channels, bodies of water, etc.

Waypoint names

The ON setting shows the name of each waypoint below its
symbol. The OFF setting displays just the symbol itself.

Page 54 958 Operator’s Manual, Rev. A

Chapter 4 - Using the Chart Screen

Chart edges

The ON setting shows the outlines of the charts that are on the
installed Navionics chart cartridge or the built-in maps. Chart
edges are shown as boxes with dotted lines.

Depth

The ON setting shows depth contour lines for low, mid, and
deep water areas, for any or all of the three depth levels.

Track line

The ON setting shows your vessel’s track points (the course
you’ve already traveled). For more track display options, see
“Changing the track control” starting on page 56.

Waypoints

The ON setting shows your waypoints on the CHART screen,
and the OFF setting turns them off, with the exception of
waypoints on a route.

Nav aids

The ON setting shows nav aids from the Navionics chart
cartridge, and the OFF setting hides the nav aids.

Land masses

The ON setting shows the coloring of land masses to contrast
between water and land. The OFF setting shows only coastline,
without the coloring.

Turning the radar

overlay on and off

958 Operator’s Manual, Rev. A Page 55

Press the RADAR OVERLAY menu key to place a radar overlay
on the CHART screen (ON) or remove it (OFF). For details
about the radar overlay, see ”Overlaying radar on the chart”
starting on page 128.

Chapter 4 - Using the Chart Screen

Changing the track

control

The 958 displays your track history as a series of dots
indicating the path you’ve recently traveled. You can choose
how often to store a position fix as a point in your track
history. The 958 stores up to 1,024 position fixes. When it
reaches this limit, the 958 starts erasing the oldest points to
add your new points to the track line. The more often you
mark your track, the faster you fill up the track memory. The
maximum track length depends on how often points are
stored.

To display the TRACK CONTROL screen, press the TRACK
CONTROL menu key on the CHART SETUP/STATUS screen.

You can choose among the following options for point storage,
and the corresponding track length:

•

every 1 second for 60 minutes total

•

every 2 seconds for 120 minutes total

•

every 4 seconds for 4 hours total

•

every 8 seconds for 8 hours total

•

every 20 seconds for 20 hours total

•

every 40 seconds for 40 hours total

•

every 1 minute for 60 hours total

•

every 2 minutes for 120 hours total

- or -

Page 56 958 Operator’s Manual, Rev. A

• FREEZE TRACK (FREEZE TRACK stops the storage of any

more points, keeping the track unchanged)

Set the TRACK DISPLAY option to OFF to remove the track
display from the CHART screen, while the 958 continues to
record the track in its memory. To resume viewing your track,
change this option to ON.

To change any one of these options, use the CURSOR PAD to
move the arrow to the field you want to change, then press the
EDIT menu key. This causes the field to flash, indicating you
should press the CURSOR PAD to select the option you want.
Press the ENTER key when you’re done, or CLEAR to restore
the field to its original value.

To clear the track history displayed on the CHART screen,
press the ERASE TRACK menu key and the ENTER

Press the RETURN menu key twice to return to the CHART
screen.

Using distance and bearing mode

The 958 lets you quickly check the distance and bearing
between any two points on the CHART screen. You can also
use this function to make new waypoints that you define by
their distance and bearing from another point.

Chapter 4 - Using the Chart Screen

key.

1. Press the WAYPTS/ROUTES key to display the WAY-
POINTS AND ROUTES screen.

2. Press the DISTANCE/BEARING menu key. The 958 dis­plays your present position at the center of the CHART
screen with the cursor directly over it.

3. Press the CURSOR PAD to move the cursor to the first
location, and press the SET NEW “X” menu key. A new
“X,” or starting point, is displayed at that location. Dis­tance and bearing information from the “X” point to the
cursor’s position is displayed in the INFO BAR. You can
move the cursor to various points on the CHART screen
and see the distance and bearing from the X point as it
moves.

958 Operator’s Manual, Rev. A Page 57

Chapter 4 - Using the Chart Screen

4. To make a waypoint at the next cursor location, press the
ADD WAYPT menu key, then enter its name, symbol, or
description on the NEW WAYPOINT screen and press
ENTER to save it.

Page 58 958 Operator’s Manual, Rev. A

5

Determining Your Position

Displaying position, COG, and speed . . . . . . . . 60

Using GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using DGPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Using loran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Using Phantom Loran . . . . . . . . . . . . . . . . . . . . . . 68

his chapter explains the 958’s most basic navigational

T

function: determining your position.

958 Operator’s Manual, Rev. A Page 59

Chapter 5 - Determining Your Position

Displaying position, COG, and speed

The 958 uses a high-performance GPS receiver as its primary
source of position data, augmented by either the WAAS
satellite system, or radiobeacon differential, or both.
Depending on the type of antenna/receiver that’s connected,
the 958 can determine and display position coordinates in
several different ways:

•

as lat/lon coordinates

>

from GPS satellites alone

>

from GPS plus the radiobeacon differential system

>

from GPS plus WAAS satellites

The 958 can display position as Loran TDs if the 958 is connected to a
loran receiver. Also, it can display “Phantom Loran” coordinates; that is, if
you don’t have a loran receiver, but want to see your position as loran
TDs, the 958 will convert GPS coordinates into Loran coordinates.

Using GPS

Position, COG, and SOG are calculated from the received
satellite data, as well as time, date, and an estimate of the 958’s
accuracy. To display this position information, press the

CHART key to display the GPS POSITION screen.

NOTE:

Page 60 958 Operator’s Manual, Rev. A

Chapter 5 - Determining Your Position

You’ll see your lat/lon on the GPS POSITION screen. If GPS
data isn’t available, you’ll see dashes instead of numbers.

You can display lat/lon as either degrees, minutes, and
seconds, or as degrees, minutes, and thousandths of minutes.
For instructions, see ”Changing your display settings” starting
on page 164.

The time of day, and today’s day and date are displayed at the
bottom of the screen. You can display time in a 12- or 24-hour
format, and you can designate a specific time zone. For
instructions, see ”Changing the time zone” starting on page

182.

SOG and COG readings are the result of instantaneous
measurements from the satellite signals. GPS speed is updated
every second. You can average these readings over a short
period of time, however, by changing the GPS speed averaging
value (see ”Changing your receiver settings” starting on page

172).

The 958 displays the name of the datum currently in use in
the center of the screen. The datum describes the reference of
the chart you’re currently using. Most new charts use the
NAD83 or WGS84 datum, which are nearly identical. Make
sure the datum that the 958 uses matches the datum shown
on the chart cartridge label. Using the wrong datum can
significantly reduce accuracy. For more information on
selecting the datum for your area, contact your authorized
Northstar dealer.

A brief status summary of the GPS receiver is displayed at the
top of the screen. Table 2 describes these various GPS status
messages.

Table 2: GPS status messages

Message Meaning

COMM FAIL

3D NAV

2D NAV

958 Operator’s Manual, Rev. A Page 61

communication link or the GPS receiver has a problem

navigating with 4 or more satellites in 3-D mode

navigating with 3 satellites in 2-D mode

Chapter 5 - Determining Your Position

Table 2: GPS status messages (continued)

Message Meaning

TRACKING

ACQUIRE

SKY SEARCH

Viewing GPS

satellite status

one or more satellites are being tracked

trying to acquire satellites

searching for satellites with no previous information

To display more information about signals received from the
GPS satellites, press the SAT INFO menu key on the GPS
POSITION screen. The GPS SATELLITES screen is displayed
showing the received Signal-to-Noise Ratio (SNR) for each
satellite (the higher the ratio, the better the quality of the
satellite signals), and a satellite map indicating where the
satellites are currently located in the sky. Satellites are
identified by their PRN number, a two-digit number assigned
by the U.S. government. GPS satellites are represented by
circles; WAAS satellites are represented by hexagons.

The center of the satellite map represents the center of the sky,
and the outer (or last) ring is the horizon. The view is looking
down from above, with East to your right and West to your
left.

The following GPS data is also displayed:

Page 62 958 Operator’s Manual, Rev. A

Using DGPS

Chapter 5 - Determining Your Position

• ACCURACY: The estimated accuracy--in feet--of the GPS

system to be expected at the current time. Your position
readings should be more accurate than this estimate 95
percent of the time.

• HDOP: This is a technical measure of the quality of your

fix. HDOP (Horizontal Dilution of Precision) is calculated
from the satellites’ current positions. You’ll usually see an
HDOP value displayed immediately after the 958 is
turned on, and before it’s ready to navigate. HDOP can
range from an ideal value of slightly less than one, up to
poor values of 10 or more. Any value less than two
indicates excellent satellite configuration.

When using the 958 with optional radiobeacon DGPS , you’ll
usually see position measurements accurate to about one to
three meters, speed measurements accurate to about 0.1 knot,
and COG measurements accurate to about 0.5 degree. DGPS
corrections remove most of the errors caused by atmospheric
variations.

NOTE:

When you’re using DGPS as your navigation source, your position coordi­nates, as calculated by the 958, may actually exceed the accuracy of
some charts.

958 Operator’s Manual, Rev. A Page 63

Chapter 5 - Determining Your Position

When the DGPS indicator is displayed, it means the 958 is
using this higher level of accuracy. When you require this
additional accuracy, be sure to check often to see that either
the DGPS or WAAS indicators are present.

Displaying DGPS

status

To display more information about received DGPS corrections,
press the DGPS INFO menu key on the GPS POSITION screen.
The DGPS STATUS screen is displayed, showing the DGPS
transmitter currently used.

The upper part of the screen shows the beacon’s name,
frequency, baud rate, and the beacon’s distance and bearing
from your vessel. The lower part of the DGPS STATUS screen
shows three bar graphs:

• SNR: The Signal-to-Noise Ratio is a good measure of over-

all signal quality, and should be as high as possible. Val­ues of 15 and higher are best; anything below 10 could
indicate poor reception.

• SIGNAL: This represents the actual strength of the

received signal. This value should be as high as possible,
and it varies with distance from the differential transmit­ter.

• NOISE: The NOISE level measures the static caused by

lightning and other atmospheric effects, and should be

Page 64 958 Operator’s Manual, Rev. A

low for best results. Table 3 below describes the noise lev­els.

Noise level value Meaning

200 or less excellent

200 - 1,000 good

1,000 - 3,000 typical at night

5,000 - 10,000 thunderstorms or electrical noise

A summary of DGPS operations is displayed at the bottom of
the DGPS STATUS screen. The table below summarizes these
status messages.

Table 4: DGPS status messages

DGPS message Meaning

Chapter 5 - Determining Your Position

Table 3: Definitions of noise levels

NO CORRECTIONS

NOT INSTALLED

SC-104 IN OK

SC-104 IN FAIL

RESULTS UNKNOWN

BCN UNHEALTHY

DISABLED

INIT OR SYNCH

Beacon receiver status message is being received, but no SC-104
DGPS corrections are present.

No beacon receiver status message is being received, nor has an
external DGPS source been chosen.

An external source has been chosen, and the required data is being
received.

An external source has been chosen, but the required data isn’t
being received.

The communication link to the GPS receiver has a problem.

The beacon station in use is either unhealthy or unmonitored.

DGPS has been turned off by the user (to enable DGPS, see
”Changing your receiver settings” starting on page 172).

The GPS receiver is trying to initialize the messages from the bea­con receiver.

958 Operator’s Manual, Rev. A Page 65

Chapter 5 - Determining Your Position

Table 4: DGPS status messages (continued)

DGPS message Meaning

TOO FEW CORRECTIONS

POOR BCN DOP

OLD CORRECTIONS

DGPS IN USE/OK

UNKNOWN

Using loran

Selecting and

displaying loran

DGPS is off because not enough satellites with corrections are
available.

DGPS is off because the satellites with corrections have poor
geometry (DOP is an acronym for Dilution Of Precision).

DGPS is on, but the current corrections are older than the timeout
you’ve set in the receiver options (see ”Choosing a DGPS correc­tions time-out” starting on page 176).

DGPS is on and the corrections are current.

An unknown status code has been received from the GPS receiver.

This section explains how you can use the 958 to navigate
using displayed loran coordinates if the 958 is connected to an
loran receiver (such as the Northstar 800). If you don’t plan to
use loran, you can skip this section.

To display loran time differences (TDs) from a connected loran
receiver:

1. Press the STAR key to display the OPTIONS/SERVICE
INFO screen.

2. Press the NAVIGATION OPTIONS menu key, then select
the NAVIGATION SOURCE field.

3. Press the EDIT menu key, then press the CURSOR PAD to
display EXTERNAL LRN as the position source.

4. Press the ENTER key, then press the RETURN menu key.

5. Press the CHART key to display the GPS POSITION screen.

6. Press the CHECK LORAN key to display the LORAN POSI-
TION screen.

Page 66 958 Operator’s Manual, Rev. A

Chapter 5 - Determining Your Position

Press the L/L TDS menu key several times to display either the
particular pair of TDs you want to use, or the loran-derived
latitude/longitude.

NOTE:

If you want the 958 to display loran position coordinates from a connected
loran, the loran must support the standard NMEA 0183 “RMA” output data
sentence structure. Without this output capability, the 958 won’t receive
position data from the loran.

Checking GPS status

Viewing loran

status

Setting loran GRI

958 Operator’s Manual, Rev. A Page 67

To display GPS coordinates and signal status, press the CHECK
GPS menu key. The 958 continues to navigate using loran,

and will display loran data the next time you display the
LORAN POSITION screen.

To check the quality of signals being received by your loran,
press the LORAN INFO menu key from the LORAN POSITION
screen. The SNR for each loran transmitting station is
displayed graphically on the LORAN INFO screen.

To change the four-digit loran Group Repetition Interval (GRI),
press the SET GRI menu key on the LORAN POSITION screen.
For the 958 to accurately convert the loran’s TDs to latitude/

Chapter 5 - Determining Your Position

longitude position fixes, the GRI must correctly match the GRI
being used by your loran receiver.

Viewing loran

warnings

Three possible loran warning indicators obtained from any
Northstar 800 series loran receiver are displayed to the right of
each TD. (These indicators are available only from Northstar
800 series lorans.)

Table 5: Northstar 800 loran warning indicators

Indicator Meaning

SNR

BLNK

CYC

LOCK

The L/L indicator to the left of a TD designates it as one of the
two TDs that the loran receiver has chosen to use to calculate
latitude and longitude.

The F/L indicator to the left of a TD indicates that it has been
forced to be used to calculate latitude and longitude.

Signal-to-Noise Ratio is low—use caution

Coast Guard is transmitting a blink signal, indicat­ing a probable transmitter problem

The receiver has detected a possible cycle slip

The loran has locked onto the loran track point (this
isn’t a warning indicator, but an indication of normal
performance)

Returning to GPS

navigation

To return to using GPS signals for navigation, repeat the steps
shown for selecting loran in “Selecting and displaying loran”
on page 66, but specify GPS instead of loran.

Using Phantom Loran

If you have lists of fishing spots and other waypoints that you
recorded as loran time differences (TDs), the 958 can
automatically convert its GPS coordinates into TDs—in real
time, as you travel—letting you display your current position as

Page 68 958 Operator’s Manual, Rev. A

Chapter 5 - Determining Your Position

TDs. The accuracy from this conversion is generally better
than 500 to 1500 feet.

This feature is called Phantom Loran, which helps you move
from using loran to using GPS. Phantom Loran lets you display
your position as TDs, or enter waypoints as TDs. You can use
the 958 to simulate the full operation of a loran receiver, using
all of the 958’s navigation functions as if it was actually
receiving loran signals.

These calculated TDs won’t exactly match the positions of
previously recorded TDs obtained directly from actual loran
signals. In most areas, TD errors shouldn’t exceed one
microsecond. However, larger errors are possible in areas with
poor configuration, or for which the 958 doesn’t have
accurate, factory-programmed ASF correction points.

Selecting and

displaying Phantom

Loran

To display position coordinates as Phantom Loran TDs:

1. Press the STAR key to display the OPTIONS/SERVICE
INFO screen.

2. Press the NAVIGATION OPTIONS menu key, then high­light the NAVIGATION SOURCE option.

3. Press the EDIT menu key, then press the CURSOR PAD to
select PHANTOM LRN.

4. Press the ENTER key, then press the RETURN menu key.

5. Press the CHART key to display the GPS POSITION screen.

6. Press the CHECK LORAN key to display the PHANTOM
LORAN screen.

958 Operator’s Manual, Rev. A Page 69

Chapter 5 - Determining Your Position

Viewing Phantom

Loran TDs

Setting Phantom

Loran GRI

Checking GPS status

Checking DGPS

status

Press the L/L TDS menu key several times to display either the
particular pair of TDs you want to use, or the GPS-derived
latitude/longitude.

Press the SET GRI menu key to change the GRI to be used in
calculating the displayed TDs. Press the CURSOR PAD to
display the available GRIs one at a time. When the GRI is
correct, press the ENTER key.

Press the SAT INFO menu key to display the status of the GPS
receiver.

Press the DGPS INFO menu key to display the current status
of the differential receiver, including SNR, SIGNAL, and NOISE
values.

Page 70 958 Operator’s Manual, Rev. A

6

Understanding the Waypoints Function

Introducing waypoints . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoints . . . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoint coordinates . . . . . . . . . . . 74

Creating new waypoints . . . . . . . . . . . . . . . . . . . . 75

Creating avoidance-area waypoints . . . . . . . . 80

Editing waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Updating waypoint coordinates . . . . . . . . . . . . 84

Moving waypoints/routes between units . . . 85

Transferring waypoints to and from a PC . . . 91

his chapter explains all of the functions associated with

T

creating, displaying, editing, and managing your waypoints.

958 Operator’s Manual, Rev. A Page 71

Chapter 6 - Understanding the Waypoints Function

Introducing waypoints

The term waypoint refers to a point (a location) that you’ve
entered into the 958’s memory. The waypoint appears on the
chart with the symbol you’ve chosen. In contrast, the term nav
aid refers to a point that’s permanently stored on the
Navionics chart cartridge.

Here are some of the functions you can perform with
waypoints:

•

go to a point on the CHART screen in one step (making a
“quick” waypoint)

•

store waypoints into the 958

•

go to these waypoints

•

string these waypoints together to form routes

•

follow these routes

•

edit or erase waypoints or routes

•

plot waypoints or routes

•

transfer all waypoints (and routes) between any two 958’s

•

transfer waypoints (and routes) from the 958 to a PC, and
back again

Displaying waypoints

You can display waypoints in any of four ways:

•

A graphic (chart) view of waypoints

•

A list of up to 30 local waypoints, sorted by nearest first

•

A list of all waypoints, sorted alphabetically

•

A list of up to 30 local avoidance waypoints, sorted by
nearest first

First, press the WAYPTS/ROUTES key, then the WAYPOINTS
menu key. To view the LOCAL, ALPHA, and AVOID waypoint
lists, press the NEXT VIEW menu key. The 958 displays the
type of list at the top of the screen. Each press of the NEXT
VIEW menu key cycles through the waypoint viewing list in

Page 72 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

the order shown above. Press the CURSOR PAD to move up or
down the list. (If your 958 is new, these lists will be empty.)

WAYPOINTS CHART

displayed on the chart

WAYPOINTS (ALPHA)

alphabetical order

screen: Waypoints are

screen: All waypoints in

WAYPOINTS (LOCAL)

points within 100 nm, nearest one first

screen: Up to 30 way-

ROCKS

PILING

WRECK

AVOID1

WAYPOINTS (AVOIDANCE)

avoidance waypoints within 100 nm, nearest one
first

screen: Up to 30

958 Operator’s Manual, Rev. A Page 73

Chapter 6 - Understanding the Waypoints Function

On the chart screen

On the local screen

On the alpha screen

On the avoidance

screen

The WAYPOINTS CHART screen displays all the waypoints in
the area around the cursor, as you move the cursor around the
chart. If necessary, press the IN and OUT keys to see the
waypoints.

Note: If you’ve turned off the display of waypoints on the
CHART screen, you’ll only see waypoints that are currently in
use for navigation.

The WAYPOINTS (LOCAL) screen displays up to 30 of the
closest waypoints (within 100 nm) in order of distance from
your present position. This list is particularly useful when you
only want to deal with the waypoints in your area. Even
though you may have hundreds of stored waypoints, often the
local waypoints are the only ones you may be interested in at
the moment.

The WAYPOINTS (ALPHA) screen displays all stored waypoints
in alphabetical order. Waypoints with a digit as the first
character appear near the beginning of the list. Those starting
with a dash or parenthesis are at the end.

The WAYPOINTS (AVOIDANCE) screen displays up to 30 of the
closest avoidance waypoints (within 100 nm) in order of
distance from your present position.

Displaying waypoint coordinates

When you display a waypoint list, you can see their
coordinates in any of the following ways by pressing the

COORD OPTION menu key:

•

as lat/lon coordinates

•

as distance and bearing from your position (often the
most useful way to display coordinates, since it may be
easier to understand “3 miles north” than lat/lon digits)

•

as loran time differences

Page 74 958 Operator’s Manual, Rev. A

The small letter “S” to the right of the waypoint name tells you
that the displayed coordinates, either lat/lon or TDs, were the
ones used to originally store the waypoint.

Creating new waypoints

There are two easy ways to create new waypoints:

•

graphically--by storing their positions after pointing to
them on the CHART screen

•

numerically--by entering position coordinates as lat/lon,
loran TDs, or distance and bearing on the NEW WAYPOINT
screen

Chapter 6 - Understanding the Waypoints Function

Assigning a name

and description

Assigning a symbol

To permanently store a waypoint, you must give it a name.
The name can be from one to six characters long, and must be
different from all the other waypoint names stored in the 958.
You can also enter a description of up to 16 characters on the
line below the name.

You can give the waypoint a symbol so you can easily identify
it on the CHART screen. When creating or editing waypoints,
you can choose from any one of 16 symbols, eight of which
are shown below.

ANCHOR FISH FLAG X

FUEL WRECK DANGER DOT

Figure 4: Waypoint symbols

958 Operator’s Manual, Rev. A Page 75

Chapter 6 - Understanding the Waypoints Function

Entering waypoints

graphically (on the

chart screen)

To enter waypoints on the CHART screen:

1. Press the WAYPTS/ROUTES key.

2. Press the WAYPOINTS menu key. You may have to press
the NEXT VIEW menu key to display the graphical
WAYPOINTS screen.

3. Press the CURSOR PAD to move the cursor where you
want to add the new waypoint. You can zoom in or out, as
necessary, to precisely place your waypoint.

4. Press the ADD WAYPT menu key to display the NEW
WAYPOINT screen.

Page 76 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

5. Enter a name for the waypoint and, if you want, a
description, as previously described.

6. Choose a symbol for the waypoint by pressing the
SYMBOL menu key to find a symbol you want (see
”Assigning a symbol” starting on page 75).

7. Adjust the coordinates, if desired.

The position coordinates displayed in the lat/lon box are
the ones designated by the cursor location on the screen.
You can adjust them here, if necessary, after pressing the

CURSOR PAD to move the cursor down into the LAT and
LON fields.

If you want to switch among displaying coordinates as
lat/lon, as loran TDs, or as distance and bearing, press the

COORD TYPE menu key:

>

For loran TDs, you can enter any legitimate pair of TDs
and the GRI for the pair. After entering the GRI, check
the name of the GRI that’s automatically displayed to
ensure it’s correct.

>

For distance and bearing from your present position,
leave the FROM point set to -HERE-, and enter the
bearing and the distance to the desired waypoint.

>

For distance and bearing from any other stored
waypoint, press the FROM menu key to display a list of
waypoints. Press the CURSOR PAD to select the desired
waypoint and press the ENTER key. Enter the bearing
and the distance from the designated waypoint to the
new waypoint. If you change your mind and want to
return to specifying distance and bearing from your
present position instead of from another waypoint, press
the FROM HERE menu key on the waypoint list screen.

NOTE:

If you’ve travelled to a part of the world that’s south of the Equator or east
of the Prime Meridian (running through Greenwich, England), the 958

or E, respectively,

automatically displays your lat/lon coordinates as
instead of
hemispheric values if necessary. When the cursor is flashing anywhere in

LAT

the
spheric values.

and W. The

N

or

LON

N-S-E-W

fields, press the

key lets you manually change these

N-S-E-W

S

key to change the hemi-

958 Operator’s Manual, Rev. A Page 77

Chapter 6 - Understanding the Waypoints Function

8. Press the ENTER key to store the new waypoint and
return to the graphical WAYPOINTS screen.

Entering waypoints
numerically (on the

list screen)

To enter waypoints numerically:

1. Press the WAYPTS/ROUTES key.

2. Press the WAYPOINTS menu key.

The 958 displays a waypoint list if you had displayed a list
during a previous viewing; however, if you had previously
displayed a graphical screen, you must press the NEXT
VIEW menu key to display the list views. These list views
comprise waypoints listed numerically in order of
distance (WAYPOINTS LOCAL list, as shown below),
alphabetically (WAYPOINTS ALPHA list), or by avoidance
(WAYPOINTS AVOIDANCE list).

Page 78 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

3. Press the ADD key to display the NEW WAYPOINT screen.

4. Enter a waypoint name and optional description.

5. Choose a symbol for the waypoint by pressing the
SYMBOL menu key to find the symbol you want.

6. Enter the waypoint’s coordinates. If you want to switch
among displaying coordinates as lat/lon, as loran TDs, or
as distance and bearing coordinates, press the COORD

TYPE menu key:

>

For loran TDs, enter any legitimate pair of TDs and the
GRI for the pair. After entering the GRI, check the name
of the GRI that’s automatically displayed to ensure it’s
correct.

>

For distance and bearing from your present position,
leave the FROM point set to -HERE-, and enter the
bearing and the distance to the desired waypoint.

>

For distance and bearing from any other stored
waypoint, press the FROM menu key to display a list of
waypoints. Press the CURSOR PAD to select the desired
waypoint and press the ENTER key. Enter the bearing
and the distance from the designated waypoint to the
new waypoint. If you change your mind and want to
return to specifying distance and bearing from your
present position instead of from another waypoint, press
the FROM HERE menu key on the waypoint list screen

958 Operator’s Manual, Rev. A Page 79

Chapter 6 - Understanding the Waypoints Function

7. Press the ENTER key to permanently store the new
waypoint, which you can edit or delete at any time.

Don’t enter a number into the
make this waypoint an avoidance point, as described below.

Creating avoidance-area waypoints

You can make avoidance areas from new or existing
waypoints. If you travel into an avoidance area, the 958 will
sound a beeping alarm and flash the star symbol on the
screen.

The 958 displays an avoidance area on the CHART screen as a
waypoint surrounded by a circle. The circle is the avoidance
area’s warning radius, which you set when you create or edit
the waypoint. The 958 gives you the option to use the
international “slashed circle” no-entry symbol as the avoidance
point’s symbol to help you quickly see it on the chart.

NOTE:

WARN RADIUS

box unless you want to

Page 80 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

CAUTION!

The avoidance alarm is only as an extra safety feature to help
alert you to possible hazards. It doesn’t replace local knowl­edge, proper use of charts, the person on watch, or any other
aspects of good seamanship that are required to safely navi­gate.

NOTE:

The waypoint is treated as an avoidance point only if you specify a warn­ing radius larger than zero. In other words, just assigning a waypoint with
the slashed circle symbol doesn’t mean the 958 will treat that waypoint
like an avoidance point. Also, you must turn on the 958’s avoidance area
alarm (see “Setting the avoidance-area alarm” on page 82).

To make a new waypoint into an avoidance area:

1. Press the WAYPTS/ROUTES key, then press the
WAYPOINTS key.

2. Press the ADD menu key to display the NEW WAYPT
screen.

3. Enter a distance in the WARN RADIUS box at the bottom
of the screen. The warning radius can be as large as 4.9
nautical miles. Be sure to allow a little extra distance
around the hazard area so you’ll have time to respond, by
turning or stopping after you hear the alarm, and to allow
for the typical accuracy of the navigation source in use.

To make an existing waypoint into an avoidance area:

1. Press the WAYPTS/ROUTES key, then press the
WAYPOINTS key. If necessary, press the NEXT VIEW
menu key to display the waypoint list screen.

2. Use the CURSOR PAD to select the desired waypoint,
then press the EDIT menu key.

958 Operator’s Manual, Rev. A Page 81

Chapter 6 - Understanding the Waypoints Function

3. Move the cursor to the WARN RADIUS box at the bottom
of the screen, and enter the warning radius—up to 4.9 nm.

4. Press the ENTER key.

Setting the

avoidance-area

alarm

Page 82 958 Operator’s Manual, Rev. A

If you’ve made a waypoint into an avoidance area, the 958 will
sound an alarm when you enter that area, but only if you’ve
turned on the alarm.

To set the audible avoidance-area alarm:

1. Press the STAR key to display the ALARMS screen.

2. Press the CURSOR PAD to select the ALARM AUDIO
option.

3. Press the EDIT ALARM menu key.

4. Press the CURSOR PAD to change the setting to ON.

5. Press the ENTER key to make your selection, or CLEAR to
leave it unchanged.

NOTE:

If you want to set the 958’s alarm to sound only when you enter an avoid-

cross track, arrive radius, and DGPS

ance area, turn off the anchor drag,
alarms. The alarm will now beep only when you enter an avoidance area,
(or when you lose GPS or loran navigation signals, but for no other rea­son).

Editing waypoints

Chapter 6 - Understanding the Waypoints Function

You can change any information about an existing waypoint
(except for the type of coordinates used to save it) or erase it
entirely by using the 958’s waypoint editing function.

Changing waypoints

To change a waypoint’s name, description, position
coordinates, or warning radius:

1. Press the WAYPTS/ROUTES key, then the WAYPOINTS
menu key. The 958 displays waypoints in whatever format
you last used: WAYPOINTS CHART screen, WAYPOINTS
(LOCAL) screen, WAYPOINTS (ALPHA) screen, or
WAYPOINTS (AVOIDANCE) screen. If necessary, press the
NEXT VIEW menu key to display the format you want.

2. To select a waypoint on the list screens, press the

CURSOR PAD. To select a waypoint on the WAYPOINTS
CHART screen, move the cursor onto the waypoint to

highlight it.

3. To edit a waypoint on a list screen, press the EDIT menu
key. To edit a waypoint on the WAYPOINTS CHART screen,
press the EDIT WAYPT menu key.

958 Operator’s Manual, Rev. A Page 83

Chapter 6 - Understanding the Waypoints Function

The EDIT WAYPOINT screen appears, allowing you to make
changes just as if you were entering a new waypoint. Press
ENTER when done.

If there’s a warning radius entered, set it to zero if you want to
remove the avoidance feature from this waypoint.

Note: If you move the waypoint, any routes containing this
waypoint will be changed.

Erasing waypoints

To permanently erase the waypoint, press the ERASE menu
key on the EDIT WAYPT screen, then press the ENTER key.

NOTE:

You can’t erase a waypoint if it’s used in a route—you must first remove it
from the route. For details about editing routes, see ”Editing a route” start­ing on page 100.

Updating waypoint coordinates

Before electronic chart navigators, a waypoint’s position was
usually taken from a paper chart by measuring the
approximate coordinates with whatever accuracy the chart
allowed. When you travelled to that waypoint, however, its
position might have been slightly different than what you
expected.

Page 84 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

With the 958’s coordinates’ update feature, when you get to
the actual spot location of the waypoint, you can update the
waypoint by setting its coordinates to your present position.
You can do this on the WAYPOINTS CHART screen or any of
the waypoint list screens.

You can also use this same feature to convert approximate
loran TD coordinates to precise GPS coordinates.

Updating from the

chart screen

Updating from a

list screen

To update the waypoint’s coordinates to your exact position at
the moment you press the UPDATE COORD menu key:

1. Select the desired waypoint on the CHART screen (its
name and coordinates are displayed in the INFO BAR).

2. Press the WAYPTS/ROUTES key, then WAYPOINTS menu
key. If necessary, press the NEXT VIEW key to display the
WAYPOINTS CHART screen, then press the EDIT WAYPT
menu key.

3. When ready, press the UPDATE COORD menu key.

4. Press the ENTER key (or press CLEAR to cancel).

1. Press the WAYPTS/ROUTES key, then the WAYPOINTS
menu key.

2. If necessary, press the NEXT VIEW menu key to show the
LOCAL screen. Press the CURSOR PAD to select the
desired waypoint.

3. Press the EDIT menu key.

4. Press the UPDATE COORD menu key.

5. Press the ENTER key (or press CLEAR to cancel).

Moving waypoints/routes between units

The 958’s import/export function lets you transfer all
waypoints and routes between two 958’s (or Northstar 941,
951, or 952).

NOTE:

To import or export waypoints and routes to and from older Northstar
units, these older units must have software version 3.12 or higher

958 Operator’s Manual, Rev. A Page 85

Chapter 6 - Understanding the Waypoints Function

installed. To obtain any necessary upgrades, please see your authorized
Northstar dealer.

You can import and export waypoints and routes between the
following Northstar units:

•

two 958’s

•

a 958 and a 952, or 951, or 941

Only one unit, called the “master,” actually enters the
import/export function. The other unit can remain in normal

operation, including the displaying of different screens, as
long as you do not add or change any of its waypoints or
routes during the actual transfer process. You can designate

either of the units to be the master since both units have the
ability to import and export waypoints and routes. However,
once you do select the master unit, just be sure to choose the
right function for what you want to do: import waypoints and
routes from the second unit, or export waypoints and routes to
the second unit).

Connecting the two

units

Moving waypoints

and routes into a

unit

The two units must be properly connected with the correct
cabling, interface ports, and port setting. For interfacing infor­mation, contact your authorized Northstar dealer.

When you move waypoints and routes into unit 1 (the
designated master) from unit 2, the entire contents of unit 2 are
imported into unit 1. Also, if any exact waypoint or route name
matches exist, the waypoints or routes from unit 2 will
overwrite the waypoints or routes already in unit 1.

NOTE:

If you press any function key on the master unit during the transfer, the
error message
the process will be aborted, and the master unit will display the particular
screen accessed by that function keypress. You can press any key on the
other unit, however, without interrupting the transfer process.

To purposely stop the transfer at any time, press the
press the

TRANSFER ABORTED BY KEY HIT

message

TRANSFER ABORTED BY KEY HIT

key, the master unit displays the dialog-box message

STOP

, and the status bar displays the

TRANSFER ABORTED

. Waypoints and routes transferred up

will be displayed,

key. If you

STOP

Page 86 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

to that point are in the receiving unit (be aware that a particular route may
not comprise all of its waypoints due to the transfer interruption). Press
the

START

that all waypoints and routes, not just the ones already in the receiving
unit and the ones left to be transferred, are re-transferred).

key again to re-start the entire transfer process (this means

1. Choose the unit you’d like to use as the master.
Remember: You can use either of the two units because
both units are capable of importing or exporting
waypoints and routes. Make sure the second unit is on.

2. At the master unit, press the WAYPTS/ROUTES key to
display the WAYPOINTS AND ROUTES screen.

3. Press the IMPORT/EXPORT menu key to display the
IMPORT/EXPORT screen.

958 Operator’s Manual, Rev. A Page 87

Chapter 6 - Understanding the Waypoints Function

4. Press the IMPORT menu key to display the IMPORT DATA
screen. The status bar in the center of the screen displays
the message READY TO TRANSFER to show that the
transfer is ready to start.

5. Before transferring, you can check the communication
link between the two units by pressing the TEST COMM
key. The status bar should display the message REMOTE
LINK OK.

6. To move waypoints and routes into this master unit from
the other unit, press the START key. The status bar
displays the message TRANSFERRING and updates every
second with the number of waypoints and routes already
received against the total quantity to be received. The
progress bar, located below the status bar, graphically
displays the percentage completed.

If there’s a problem with the transfer process, the
following messages may appear:

•

If the other unit is off-line, the master unit displays the
dialog-box message COULDN’T GET REMOTE

WAYPT/ROUTE COUNT and the status-bar message
COMMUNICATION ERROR.

•

If the other unit doesn’t have any waypoints and routes,
the master unit displays the dialog-box message NO

Page 88 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

WAYPTS OR ROUTES TO TRANSFER and the status-bar
message NO TRANSFER DONE.

•

If the master unit is completely full of waypoints and
routes with no more room available, the master unit
displays the dialog-box message LOCAL UNIT STATUS

ERROR [002] DATABASE FULL and the status-bar message
COMMUNICATION ERROR.

7. If the transfer is successful, the master unit’s status bar
displays the message TRANSFER COMPLETE. You can now
press any key to resume other operations.

Moving waypoints

and routes from a

unit

When you move waypoints from unit 1 (the designated
master) into unit 2, the entire contents of unit 1 are exported
into unit 2. Also, if any waypoint or route name matches exist,
the waypoints or routes from unit 1 will overwrite the
waypoints or routes already in unit 2.

NOTE:

If you press any function key on the master unit during the transfer, the
error message
the process will be aborted, and the master unit will display the particular
screen accessed by that function keypress. You can press any key on the
other unit without interrupting the transfer process.

To purposely stop the transfer at any time, press the
press the

TRANSFER ABORTED BY KEY HIT

message
to that point are in the receiving unit (be aware that a particular route may
not comprise all of its waypoints due to the transfer interruption). Press

START

the
that all waypoints and routes, not just the ones already in the receiving
unit and the ones left to be transferred, are re-transferred).

TRANSFER ABORTED BY KEY HIT

key, the master unit displays the dialog-box message

STOP

, and the status bar displays the

TRANSFER ABORTED

key again to re-start the entire transfer process (this means

. Waypoints and routes transferred up

will be displayed,

key. If you

STOP

1. Choose the unit you’d like to use as the “master.”
Remember: You can use either of two units because both
units are capable of importing or exporting waypoints and
routes. Make sure the second unit is on.

2. At the “master” unit, press the WAYPTS/ROUTES key to
display the WAYPOINTS AND ROUTES screen.

958 Operator’s Manual, Rev. A Page 89

Chapter 6 - Understanding the Waypoints Function

3. Press the IMPORT/EXPORT menu key to display the
IMPORT/EXPORT screen.

4. Press the EXPORT menu key to display the EXPORT
DATA screen. The status bar in the center of the screen
displays the message READY TO TRANSFER to show that
the transfer is ready to start.

5. Before transferring, check the communication link
between the two units by pressing the TEST COMM key. If
the status bar now displays the message REMOTE LINK

OK, you may begin to transfer waypoints.

Page 90 958 Operator’s Manual, Rev. A

Chapter 6 - Understanding the Waypoints Function

6. To move waypoints and routes from this unit into the
other unit, press the START key. The status bar displays
the message TRANSFERRING and updates every second
with the number of waypoints and routes sent compared
to the total quantity to be sent. The progress bar, located
below the status bar, graphically shows the percentage
completed.

If there’s a problem with the transfer process, the
following messages may appear:

•

If the other unit is off-line, the master unit displays the
dialog-box message TRANSFER ABORTED BY

COMMUNICATION TIMEOUT and the status-bar message
COMMUNICATION ERROR.

•

If the master unit doesn’t have any waypoints and routes,
the master unit displays the dialog-box message NO
WAYPTS OR ROUTES TO TRANSFER and the status-bar
message NO TRANSFER DONE.

•

If the other unit is completely full of waypoints and routes
(no more room available), the master unit displays the
dialog-box message REMOTE UNIT STATUS ERROR [002]

DATABASE FULL and the status-bar message TRANSFER
ERROR.

7. If the transfer is successful, the status bar displays the
message TRANSFER COMPLETE. You can now press any
key to resume other operations.

Transferring waypoints to and from a PC

If you’ve stored many waypoints or routes in the 958, or if
these waypoints are the only record you have of these
important locations, you may want to keep a separate copy on
your PC.

You can transfer waypoints and routes to your PC by using
Northstar’s loader cable (part number 1100-LC) and special
transfer software provided by third-party vendors. This lets
you copy, edit, or plot waypoints and routes, and, most
important, reload them from your PC into your 958 if they’re
accidentally erased or lost due to equipment failure. For

958 Operator’s Manual, Rev. A Page 91

Chapter 6 - Understanding the Waypoints Function

transfer software and instructions, and cable ordering
information, contact your authorized Northstar dealer.

Page 92 958 Operator’s Manual, Rev. A