Garmin GPS 120XL User Manual

®

GPS 120XL

ZOOM

Marine

Navigator

Owner’s Manual

&

Reference

Software Version 2.0 or above
© 1997 GARMIN Corporation

1200 E. 151st Street, Olathe, KS USA 66062
Tel: [phone] or 800-800-1020
Fax: [phone]
Web Site Address: www.garmin.com

GARMIN (Europe) Ltd.
Unit 5,
The Quadrangle, Abbey Park Industrial Estate,
Romsey, SO51 9AQ, U.K.
Tel: [phone]
Fax: [phone]

GARMIN (Asia) Corp.
4th Fl., No. 1., Lane 45,
Pao-Hsing Road,
Hsin Tein,
Taiwan R.O.C.
Phone: [phone]
Fax: [phone]

All rights reserved. No part of this manual may be reproduced or transmitted in any
form or by any means, electronic or manual, including photocopying and recording, for
any purpose without the express written permission of GARMIN.

Information in this document is subject to change without notice. GARMIN reserves
the right to change or improve its products and to make changes in the content without
obligation to notify any person or organization of such changes or improvements.

GARMIN, Personal Navigator, AutoLocate,TracBack, and MultiTrac 8 are all trade­marks of GARMIN Corporation and may not be used without the expressed permission
of GARMIN.

July 1997 - Part #190-00136-00 Rev. B - Printed in Taiwan.

INTRODUCTION

GPS 120XL

OPERATOR’S

Overview

MANUAL

Welcome to the easiest-to-use fixed-mount GPS on the water!
The GPS 120XL represents GARMIN’s continuing commitment to provide
mariners with quality navigation information in a versatile, accurate and user­friendly design which will be useful for years to come. To get the most from
your new GPS unit, it is important that you take the time to read through the
operator’s manual to understand the operating features of the GPS 120XL.
The manual is organized into four sections for your convenience:

Introduction gives a quick overview of the manual and contains the
table of contents and glossary of navigation terms.

Getting Started takes you through step-by-step instructions to initialize
the receiver for first-time use and introduces you to the basic features of the
unit with a quick-start orientation to the GPS 120XL. This section has been
designed to acquaint you with the unit and provide a basic working knowl­edge necessary to use the unit in typical conditions.

Reference provides detailed explanations of the advanced features and
operations of the GPS 120XL in a topical format. This allows you to concen­trate on a specific topic quickly, without reading through entire sections of
text that you may not need.

The Appendix section contains installation instructions and items with
multiple listings, such as: map datams, time offsets, and the index.

Packing List

Before getting started with your GPS receiver, check to see that your
GARMIN GPS 120XL package contains the following items. If you are miss­ing any parts, please contact your dealer immediately.

Standard Package:

• GPS 120XL Unit • Mounting Bracket with knobs

• External Antenna with 30’ cable • Owner’s Manual

• Power/Data Cable • Quick Reference Card

See your GARMIN dealer for accessories, including our PC kit.

Thanks for choosing the GARMIN GPS 120XL. We hope it will help you
meet all of your navigation needs.

i

INTRODUCTION

Caution

The GPS system is operated by the government of the United States,
which is solely responsible for its accuracy and maintenance. The system is
subject to changes which could affect the accuracy and performance of all
GPS equipment. Although the GPS 120XL is a precision electronic
NAVigation AID (NAVAID), any NAVAID can be misused or misinterpreted
and, therefore, become unsafe.

Use the GPS 120XL at your own risk. To reduce the risk of unsafe
operation, carefully review and understand all aspects of this Operator’s
Manual and thoroughly practice operation using the simulator mode prior to
actual use. When in actual use, carefully compare indications from the GPS
120XL to all available navigation sources including the information from
other NAVAIDs, visual sightings, maps, etc. For safety, always resolve any dis­crepancies before continuing navigation.

NOTE: This device meets requirements for Part 15 of the FCC limits for
Class B digital devices for home or office use. It has been tested for compli­ance with all necessary FCC standards. This equipment generates, uses, and
can radiate radio frequency energy and, if not installed and used in accor­dance with the instructions, may cause harmful interference to radio commu­nications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to
other equipment, which can be determined by turning the equipment off and
on, the user is encouraged to try and correct the interference by relocating the
equipment or connecting the equipment to a different circuit than the affected
equipment. Consult an authorized dealer or other qualified service technician
for additional help if these remedies do not correct the problem. Operation is
subject to the following conditions: (1) This device cannot cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation. The GPS 120XL
does not contain any user-serviceable parts. Repairs should only be made by
an authorized service center. Unauthorized repairs or modifications could
void your warranty and your authority to operate this device under Part 15
regulations.

ii

INTRODUCTION

Table of

Contents

SECTION ONE Introduction

Glossary/Navigation Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

SECTION TWO Getting Started

Turning On and Initializing the Receiver . . . . . . . . . . . . . . . . . . . . . .5-7

Primary Page Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-9

Marking a Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-11

Position and Map Page Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-12

Going To a Waypoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Using the Highway Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Cancelling a GOTO and Clearing Maps . . . . . . . . . . . . . . . . . . . . . . .15

SECTION THREE Reference

Satellite Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-17

Position Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Marking, Saving, and Using Waypoints . . . . . . . . . . . . . . . . . . . . .19-26

TracBack Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27-28

Creating and Using Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29-34

Using the Compass and Highway Navigation Pages . . . . . . . . . . . .35-37

Map Plotting, Zooming, and Cursor Movement . . . . . . . . . . . . . . .38-40

Menu Page and Distance/Sun Calculation . . . . . . . . . . . . . . . . . . . . . .41

Track Log Setup and TracBack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Interface Setup and DGPS Interface . . . . . . . . . . . . . . . . . . . . . . . .43-45

System Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46-47

Navigation Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48-50

Map Page Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51-52

Alarms Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

Navigation Simulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

Appendix A––Unit and Antenna Installation . . . . . . . . . . . . . . . . .55-57

Appendix B—Specifications and Wiring . . . . . . . . . . . . . . . . . . . .58-59

Appendix C—Messages/Time Offsets . . . . . . . . . . . . . . . . . . . . . . .60-61

Appendix D—Map Datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62-64

Appendix E—Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65-66

1

INTRODUCTION

Glossary

The GPS 120XL is a powerful navigation tool that can guide you anywhere
in the world. To better understand its operation and capabilities, it may be
helpful to review the basic terms and concepts briefly explained below.

Other navigation and GPS definitions used in the manual are defined in the
appropriate reference sections of the manual.

Almanac Data

Satellite constellation information (including location and health of satellites)
that is transmitted to your receiver from every GPS satellite. Almanac data must
be acquired before GPS navigation can begin.

Bearing

The compass direction from your position to a destination.

Course Made Good (CMG)

The bearing from the “active from” position (your starting point) to your

present position.

Crosstrack Error (XTE)

The distance you are off a desired course in either direction.

Desired Track (DTK)

The compass course between the “from” and “to” waypoints.

Differential GPS (DGPS)

An extension of the GPS system that uses land-based radio beacons to trans­mit position corrections to GPS receivers.

Estimated Time of Arrival (ETA)

The time of day of your arrival at a destination.

Estimated Time Enroute (ETE)

The time left to your destination at your present speed.

2

INTRODUCTION

Glossary

Grid

Coordinate system that projects the earth on a flat surface, using square
zones for position measurements. UTM/UPS and Maidenhead formats are
grid systems.

Ground Speed

The velocity you are traveling relative to a ground position.

Latitude

The north/south measurement of position perpendicular to the earth’s
polar axis.

Longitude

An east/west measurement of position in relation to the Prime Meridian,

an imaginary circle that passes through the north and south poles.

Navigation

The process of traveling from one place to another and knowing where

you are in relation to your desired course.

Position

An exact, unique location based on a geographic coordinate system.

Track (TRK)

The direction of movement relative to a ground position.

Universal Transverse Mercator (UTM)

A grid coordinate system that projects global sections onto a flat surface to

measure position in specific zones.

Velocity Made Good (VMG)

The speed you are traveling in the direction of the destination.

Waypoint

A specific location saved in the receiver’s memory.

3

INTRODUCTION

NORTH

“ACTIVE FROM”

WAYPOINT

NORTH

DTK

CROSSTRACK ERROR

BRG

TRK

GROUND SPEED

DISTANCE

“ACTIVE TO”

WAYPOINT

“ACTIVE LEG”

Navigation

Basics

The GPS 120XL provides steering guidance and navi­gation information using degrees, a measurement measured
in a clockwise direction from a north reference. North is
described as 000º, east as 090º, south as 180º, and west as
270º. The diagram and compass rose below provide a graphic
illustration of the navigation terms used by the GPS 120XL.
More information on basic navigation and GPS are available
at your local library or bookstore.

4

Getting Started with your GPS

Welcome to the exciting world of GARMIN GPS!
The GPS 120XL represents GARMIN’s continuing com­mitment to provide marine users with quality naviga­tion information in a versatile, user-friendly design they
will enjoy for years to come. To get the most out of
your GPS receiver, be sure to read through the initial­ization and Getting Started sections of this manual, and
refer to the reference section for complete details on
the GPS 120XL’s advanced features.

Initializing Your GPS for First-Time Use

The first time you power up your new GPS 120XL
is an important step in getting the best possible future
GPS performance.

Because a GPS receiver can only receive signals
from satellites above the horizon, it needs to know
what satellites to look for at any given time. By using
an almanac (a timetable of satellite numbers and their
orbits) stored in the receiver’s memory, the GPS 120XL
can determine the distance and position of any GPS
satellite and then use this information to determine
your position.

To obtain this almanac data, your GPS receiver
needs to be initialized -- or given the opportunity to
“find itself”-- the very first time it is turned on. Once
you have initialized the unit, the GPS 120XL will com­pute future fixes more rapidly, usually in a few
minutes.

Remember that initializing the unit is only neces­sary under the following conditions:

• First-time use from the factory

• If the receiver has been moved over 500 miles
from the last calculated position with power off

• If the receiver’s memory has been cleared and all
stored data has been lost

GETTING

STARTED

Initialization

Welcome Page

The welcome page will
appear as soon as the GPS
120XL is turned on and
remain while the unit con­ducts a brief self-test.

5

GETTING

STARTED

Initialization

The EZinit prompt will
automatically appear if the
receiver needs to be initial­ized. The prompt may also
appear during normal use if
the antenna is shaded.

Initializing the Receiver

The receiver is shipped from the factory in
AutoLocate™ mode, which enables the GPS 120XL to
determine its location anywhere in the world. To speed
up the initialization process, we recommend using the
graphic initialization described below, which will usual­ly provide a fix in 7.5 to 15 minutes.

Before you initialize, make sure your GPS 120XL
unit and antenna have been correctly installed on your
boat according to the instructions in Appendix A.

To turn the GPS 120XL on:

1. Press and hold Puntil the receiver turns on.

The welcome page will be displayed while the unit
conducts a self test.

Once testing is complete, the welcome page will be
replaced by the Satellite Page, with the EZinit prompt
ready for you to select one of two initialization
methods:

•Select Country––allows you to initialize the
receiver by selecting your present position from a
list of countries in the GPS 120XL’s internal data­base. This usually provides a position fix in a few
minutes.

TM

•Autolocate

––allows the GPS 120XL to initialize
itself and calculate a position fix without knowing
your present position. This usually provides a posi­tion fix in 7.5-15 minutes.

If the EZinit prompt has not automatically
appeared on the Satellite Page:

Use the arrow keypad to
highlight the country,
region or state of your pre­sent position from the list
and press ENTER. If the
country is not listed, select
the closest country instead.

6

1. Press the Fkey.

Note: If the EZinit prompt ever appears after you
have initialized the receiver (due to the antenna’s view
of satellites being obstructed by trees, etc.), highlight
the ‘no re-init’ selection with the arrow keypad and
press ENTER.

To initialize the receiver:

1. If the ‘country’ option is not highlighted, press the
key repeatedly to move the field highlight to the ‘coun­try’ option.

2. Press the

F

key.

D

Initializing the Receiver (cont)

3. Use theDkey to scroll through the list options until
the country of your present position appears.

4. Use the

U

you’re in. If the country you’re in is not listed, select
another country within 500 miles of your present
position.

key to highlight the country/state/region

GETTING

STARTED

Initialization

5. Press

F

to finish.

The GPS 120XL will now begin searching for the
appropriate satellites for your location and should
acquire a position within 3-5 minutes. You can verify
that you have acquired a position by watching the
Satellite Page transition to the Position Page (provided
you haven’t pressed any other buttons) or by looking for
a ‘2D NAV’ or ‘3D NAV’ status at the top left corner of
the Satellite Page.

Initialization Troubleshooting

If you have trouble initializing the receiver or
acquiring a position, check the following:

• Does the antenna have a clear view of the sky?

If there are large buildings or mountains nearby, or

if there is heavy tree cover, the receiver may not be

receiving enough satellite signals to calculate a

position.

• Have you selected the right country/state/region
from the EZinit list?

Check for the correct approximate lat/lon on the
Position Page, or reselect the appropriate country
from the list to restart the initialization.

• Have you moved more than 500 miles from the
last calculated position with the receiver off?

Reinitialize the receiver, selecting the country/state/
region of your new location from the EZinit list.

Your unit should now be initialized. If you want to
complete the Getting Started Tour at another time, you
may now turn the GPS 120XL off (see below) or you
may continue.

To turn the GPS 120XL off:

1. Press and hold Pfor approximately three seconds
until the receiver turns off.

The GPS 120XL’s Satellite
Page will help you deter­mine which satellites are in
view and whether or not
any satellites are being
“shaded” or blocked from
the receiver’s antenna.

By monitoring the signal
strength bars at the bottom
of the page and the sky view,
you’ll be able to see how
moving to another area with
a clearer view of the sky will
improve satellite reception
and speed up signal
acquisition.

7

GETTING

STARTED

Primary Pages

Satellite Page

The Satellite Page will
allow you to monitor satel­lite signal reception and
strength.

Primary Pages

Before we start the tour, let’s briefly look at the five
primary information pages used for the GPS 120XL.
Note: Switch between pages by pressing either the
or Jkeys.

Q

J

Q

Satellite Page

The Satellite Page shows satellite positions and
signal strength. Satellite positions are displayed using
two circles and a center point. The outer circle shows
satellites on level with the horizon; the inner circle is
45º above the horizon; and the center point represents
satellites directly overhead. Knowing satellite positions
will show you the direction of any blocked signals.

The bottom of the page contains a row of signal
strength bars corresponding to each satellite being used.

Position Page

The Position Page shows you where you are, what
direction you’re heading and how fast you’re going.

The top of the page contains a compass tape which
is a graphic representation of your heading. Your track
and speed are indicated immediately below.

Position Page

8

The graphic compass tape reflects your head-

!

#

ing only while you are moving.

The rest of the page shows your current position in
three dimensions: latitude, longitude and altitude. A
trip odometer and 12/24 hour clock are also provided.

Map Page

The Map Page acts as a window. It allows you to
view your position, the “path” you have traveled over,
and nearby waypoints.

A diamond icon in the center of the screen repre­sents your current position. As you move, you will see
a thin line-- called a track log-- appear along the path
you have just covered. Names of stored waypoints can
also be shown on the map.

The bottom corners of the screen will always dis­play your current track and speed. When going to a
waypoint, highlighting an on-screen waypoint, or using
the panning target crosshair, the corresponding dis­tance and bearing are shown at the top corners of the
screen.

GETTING

STARTED

Map, Navigation

& Menu Pages

Navigation Page

A navigation page gives you steering guidance
when going to a waypoint. The GPS 120XL has two
navigation page choices: the Highway Page and the
Compass Page. The Highway Page is the default and
will be briefly explained here. The Compass Page is
covered on pages 35 and 37.

The Highway Page uses a graphic highway to
show your movement in relation to your desired
course. The upper section shows bearing and distance
to the waypoint and your current track and speed. The
middle portion contains the actual highway. The high­way indicates the crosstrack error, or distance and
direction, your are off-course from your waypoint.
Always turn in the direction the highway is pointing.
For example, if the highway points straight up, no turn
is required. If the highway points right, you need to
turn right until the highway points straight up. The
remainder of the page contains the estimated time
enroute (ETE) and your velocity made good (VMG).

Menu Page

The last primary page is the Menu Page. The
Menu Page gives you access to the GPS 120XL’s way­point management, route, track log, and setup features
through a list of submenus.

Map Page

Shows your progress on a
moving track plotter and
get a bird’s-eye-view of sur­rounding waypoints with
the Map Page.

Highway Page

With the Highway Page,
you will get graphic steer­ing guidance in navigating
a route or to a single way­point.

9

GETTING

STARTED

Marking A

Position

The simulator mode will
allow you to practice navi­gation and become familiar
with the GPS 120XL with­out leaving your slip.

Getting Started Tour

Now that your GPS receiver has been initialized and
you are familiar with the primary pages, it’s time to take
a tour. This is a live tour and is to be conducted with
your unit installed and with the boat in the water. The
tour will take you through the receiver’s basic features
and functions as you move about on the water and
assumes that the GPS 120XL is turned on, initialized,
and that you have not changed any of the factory set­tings (units of measure, selectable fields, etc.). If these
settings have been changed, the pictures and descrip­tions in this manual may not match what you see on
your screen.

Navigation Simulator

If you are not able to take the Getting Started Tour
with your boat in the water, you may use the built-in
navigation simulator to practice using the GPS 120XL.
To use the simulator, see page 54.

Marking a Waypoint

To begin the tour, let’s take the position you have
acquired (either by just initializing the unit or by having
turned the unit on) and mark it as a waypoint for future
reference.

To save a waypoint with the
default three-digit name,
simply press the MARK key
followed by the ENTER key.
The GPS 120XL will then
return to the page previous­ly displayed.

10

1. Press the Mkey to capture and hold your position.

To mark a position, you must have obtained a

!

#

2D or 3D fix, or have the receiver in simulator
mode. If you try to mark a position without a
position fix, you will be alerted with a ‘No GPS
Position’ message.

The mark position page will appear, showing the
captured position and a default 3-digit waypoint name.
Let’s change the default name to something a little more
meaningful, like ‘DOCK’.

1. Press theUkey twice to move the field highlight
from the ‘save’ field to the name field.

GETTING

STARTED

Marking A

Position

2. Press
name.

3. Press and hold the
alphabet until the letter ‘D’ appears.

4. Press the
to the next character space.

5. Repeat steps 3 and 4 until the word ‘DOCK’ is dis­played.

6. Press

7. Press the
the ‘save’ field.

8. Press the
the position as a waypoint named ‘DOCK’.

and Lto clear the default waypoint

F

U

key to scroll through the

R

key once to move the character highlight

to complete entry of the name.

F

key once to return the field highlight to

D

key to confirm that you want to save

F

The mark position page will now be replaced by
the Position Page (or whatever page was displayed
prior to pressing the

key). The ‘DOCK’ waypoint

M

is now stored in the GPS 120XL’s memory, and will
remain there until you manually remove it or clear the
receiver’s memory. For more on waypoint management,
see pages 19-25.

Using the Position and Map Pages

Now that you’ve marked a position, let’s see how
the Position and Map Pages can be used to monitor
your progress as you head out in to the open water.

The arrow keypad is used
for all data entry. Use the
UP and DOWN keys to
select letters, numbers, or
menu options, and use the
LEFT and RIGHT keys to
move the cursor forward or
backward along the line.

Position Page

As always, ensure your primary focus is on

!

#

boating traffic and monitor the GPS120XL
briefly when operating your boat.

11

GETTING

STARTED

Position & Map

Pages

The Map Page displays
your present position as a
diamond icon and provides
real-time graphic “bread­crumb” display of your
track right on the screen.

Using the Position and Map Pages (continued)

As you head out, the Position Page will help you

monitor your movement.

Graphic

Track Over

Ground

Tr i p

Odometer

Position
Display

Compass Tape

Current Speed

Altitude

12/24 Hour

Time

The direction you are moving (your track) and your
speed are displayed on the upper part of the page, just
below the graphic compass tape. The latitude, longitude
and approximate altitude of your position, along with a
resettable trip odometer, are continuously displayed in
the middle of the page, and the time of day is displayed
below.

Now let’s change the display to the Map Page and
watch the track log of our tour:

1. Press the Jkey to change from the Position Page
to the Map Page.

To get a larger view of the Map Page, lets change the

the zoom scale from .2 (default) to 1.0 nautical mile.

To select a larger zoom scale on the Map Page:

The moving map’s default
screen orientation is track
up orientation. “Track up”
means that your current
direction of travel is always
up (or towards the top of)
the screen. It can also be set
for north up, or desired
track orientation through
the map setup page.

12

1. Press the Hkey until ‘1.0 n.m. zoom scale’ appears.

Your current position is shown as the diamond in
the middle of the screen. The dark circle below the dia­mond represents the position you created, with the line
between the two showing your track.

1. Once you have reached an area that allows for gener­al changes in direction without interfering in the pas­sage of other boats, mark your current position again
and name this waypoint “CHANNL”. (See ‘Marking a
Waypoint’ on pages 10-11)

2. Next, make a moderate turn in any direction safe for
navigation and proceed for another 3 minutes.

Going To a Waypoint

Once you’ve stored the “CHANNL” waypoint in
memory, you can use the GPS 120XL to guide you to it
by performing a simple GOTO. A GOTO is nothing
more than a straight-line course from your present
position to the destination you’ve selected.

Use caution when navigating. A “straight-line”

!

#

course reflects the shortest distance to a waypoint,

and does not navigate around obstructions, such

as land or buoys, etc.

Now that you have moved away from ‘CHANNL’
for three minutes, let’s try navigating back to it.

To select a GOTO destination:

GETTING

STARTED

Going To A

Waypoint

1. Press the Gkey.

2. The GOTO waypoint page will appear, displaying all
the waypoints in memory in alphabetical order.

3. Use

U

or Dto highlight the ‘CHANNL’ waypoint.

4. Press the
gate to the displayed waypoint. The Highway Page
(default) will appear.

Bearing to

Waypoint

Destination

Waypoint

“Finish Line”

key to confirm that you want to navi-

F

Distance to

Destination Waypoint

CDI Scale

Waypoint

The GPS 120XL’s Highway Page provides graphic
steering guidance to a destination, with an emphasis on
a straight-line course to the desired waypoint and the
distance and direction you are off course. The bearing
and distance to a waypoint, along with your current
track and speed are displayed at the top of the screen,
with your estimated time enroute (ETE) and velocity
made good (VMG), or the speed you are approaching
your destination, shown at the bottom.

The GOTO waypoint page
allows you to select your
destination from a list of all
available waypoints in the
GPS 120XL’s memory.

Once a GOTO is activated,
the GPS 120XL will provid­ed steering guidance until
the GOTO is cancelled. To
cancel a GOTO, highlight
the cancel prompt at the
bottom of the page and
press ENTER.

13

GETTING

STARTED

Using the Highway Page (continued)

Using The

Highway Page

The 120XL will also provide
steering guidance with a
graphic compass page.

To change the display from
the highway page, press
ENTER twice.

Current Track

Position

Diamond

Estimated

Time of
Arrival

Pointer to Waypoint

Current Speed

Velocity Made

Good

As you head toward your destination, the middle
section of the screen provides visual guidance to your
waypoint on a moving graphic “highway”. The moving
arrow just below the course deviation scale always
points to your selected waypoint relative to the direc­tion you are moving.

Your present position is represented by the diamond
in the center of the course deviation scale. The line
down the middle of the highway represents your
desired track. As you navigate toward a waypoint, the
highway will actually move, indicating the direction
you’re off course, relative to the position diamond on
the CDI scale. To stay on course, simply steer toward
the center of the highway.

While navigating, you may decide to use the
Compass Page (see picture above left) instead of the
Highway Page.

Once you are one minute
from the destination (based
on your present speed and
course), an arrival message
will appear on the message
page.

14

To select the Compass Page:

1. While viewing the Highway Page press F, twice.

The Compass Page will now become the displayed
navigation page. This page provides a directional point­er to your destination, by using a rotating compass dis­play to show direction of travel. It provides better steer­ing guidance at slower speeds for travel with many
directional changes.

To switch back to the Highway Page, press ENTER
twice.

Cancelling a GOTO

If you decide to stop navigating to the active way-

point, all you have to do is cancel the GOTO.

To cancel an active GOTO:

1. Press the Gkey.

2. Use the arrow keypad to move the field highlight to
the ‘CANCEL GOTO?’ prompt at the bottom of the page
and press

F

.

Clearing a Cluttered Map Display

After you’ve used the GPS 120XL for a few trips,
you may find that your map display has become a bit
messy from keeping track of your every move. For
practice, let’s clean up the screen by clearing the track
log (the plot points left on the Map Page) we’ve just
created during the Getting Started Tour.

1. Press Jor Quntil the Menu Page appears.

2. Use the

D

‘TRACK LOG’ option.

3. Press

4. Press the
option. The clear log confirmation page will appear.

key to move the field highlight to the

to access the track log page.

F

U

key twice to highlight the ‘CLEAR LOG?’

GETTING

STARTED

Cancelling A

GOTO &

Clearing Maps

Highlight the ‘CLEAR
LOG?’ prompt and press
ENTER to clear the track
log. Once all 1024 points
are used, the oldest point
will be continuously deleted
to make room for the latest
track log point.

5. Use the

6. Press

L

key to highlight the ‘Yes’ prompt.

to finish.

F

Turning the Receiver Off

You’ve now gone through the basic operation of
your new GPS receiver and probably know a little more
than you think about how it works. We encourage you
to experiment with the GPS 120XL until it becomes an
extension of your own navigation skills. If you
encounter any problems using the unit or want to take
advantage of the GPS 120XL’s more advanced features,
refer to the reference section.

To turn the GPS 120XL off:

1. Press and hold the Pkey for 3 seconds.

Holding the POWER key
for three seconds ensures
against accidental shut-off
by accidentally pressing the
button.

15

REFERENCE

Satellite Page

Overview

As soon as a satellite has
been found and the GPS
120XL is acquiring position
data, the satellite number
will turn to normal presen­tation and a hollow bar will
appear.

Satellites being tracked but
blocked from use (03,17)
will be displayed in reverse
video, with the correspond­ing signal strength bar hol­low.

Satellite Page

Status

Satellite

Numbers

Satellite

Sky View

Satellite

Sky View

The Satellite Page displays the status of various
receiver functions. The status information will help you
understand what the GPS 120XL is doing at any given
time, and will tell you whether or not the receiver has
calculated a position fix.

Sky View and Signal Strength Bars

The sky view and signal strength bars give you an
indication of what satellites are visible to the receiver,
whether or not they are being used to calculate a posi­tion fix, and the signal quality. The sky view in the cen­ter of the page shows a bird’s-eye view of the position of
each satellite relative to the receiver’s last known posi­tion. The outer circle represents the horizon (north up);
the inner circle is 45º above the horizon; and the center
point is a position directly overhead.

When the receiver is looking for a particular satel­lite, the corresponding signal strength bar will be blank
and the sky view indicator will remain highlighted in
reverse video. Once the receiver has found the satellite,
a hollow signal strength bar will appear, indicating that
the satellite has been found and the receiver is collect­ing data from it. The satellite number in the sky view
will also change from reverse video to normal presenta­tion. As soon as the GPS 120XL has collected the neces­sary data to use the satellite for positioning, the hollow
bar will become solid.

16

Receiver Status and EPE

Receiver status is indicated at the top left of the
screen, with the current horizontal accuracy (estimated
position error, in feet or meters) at the top right. The
status will show one of the following conditions:

Searching— the GPS 120XL is looking for any

available satellites in view.

TM

AutoLocate

— the GPS 120XL is initializing and

collecting new almanac data. This process can take

7.5 to 15 minutes.

Acquiring— the receiver is collecting data from

available satellites, but has not collected enough

data to calculate a 2D fix.

2D Nav (2D Navigation)— at least three satellites

with good geometry have been locked onto and a

2-dimensional position fix (latitude and longitude)

is being calculated. ‘2D Diff’ will appear when you

are receiving DGPS corrections in 2D mode.

3D Nav (3D Navigation)— at least four satellites

with good geometry have been locked onto, and

your position is now being calculated in latitude,

longitude and altitude. ‘3D Diff’ will appear when

you are receiving DGPS corrections in 3D mode.

Poor CVG (Poor GPS Coverage)— the receiver is

no longer tracking enough satellites for a 2D or 3D

fix.

Not Usable— the receiver is unusable, possibly

due to incorrect initialization or abnormal satellite

conditions. Turn the unit off and back on to reset.

SIM (Simulating Navigation)— the receiver is in

simulator mode.

REFERENCE

Receiver Status

& EZinit

A ‘POOR CVRG’ status
will appear on the Satellite
Page if the receiver has lost
the satellites required to
compute a fix. Make sure
the external antenna is not
covered and is connected to
the GPS 120XL.

EZinit Option Prompt

The Satellite Page also provides access to the GPS
120XL’s initialization menu, the EZinit prompt. The
EZinit prompt will appear automatically the first time
the unit is turned from the factory, after 10 minutes of
unsuccessful satellite acquisition, or if you push the
ENTER key while viewing the Satellite Page with the
unit in searching, AutoLocate, acquiring, simulator, or
poor coverage modes. (See pages 6-7 for more on
EZinit.)

If you travel more that 500
miles with the receiver off,
reinitialize the unit to your
new position by using the
EZinit feature. To access
EZinit, press ENTER from
the Satellite Page before any
satellites are acquired.

17

REFERENCE

Backlighting &

Position Page

The speed and track dis­played on the Position Page
may fluxuate at slow speeds
(or when you’re standing
still) because of position
errors caused by Selective
Availability.

Screen Backlighting

The GPS 120XL features three levels of backlighting.
Activate the backlight by pressing the POWER key
briefly. Each press of the button advances the backlight­ing to the next level and then turns it off. Backlighting
will remain on until turned off. Note: a bulb icon will
appear on the Satellite Page when backlighting is on.

Position Page

The GPS 120XL’s Position Page shows you where
you are, the direction you are heading, and your speed,
and is most useful when you are traveling without an
active destination waypoint. A compass tape at the top
of the page displays your cardinal heading (while mov­ing), with current track and speed over the ground indi­cated below. The rest of the page shows your present
position in three dimensions (latitude, longitude and
altitude). The units of measure for speed, distance, posi­tion and altitude are all user-selectable through the nav­igation setup menu (see pages 48-50). The 12/24 hour
clock and time offset options are available from the sys­tem setup menu (see page 47).

Trip Odometer

The Position Page also features a resettable trip
odometer to measure your total distance traveled.

To reset the trip odometer:

To reset the trip odometer,
highlight the trip field and
press ENTER. Use the
LEFT arrow key to clear the
distance field, and press
ENTER to confirm.

18

1. Press the Dkey until the trip field is highlighted.

2. Press

3. Press

F

F

,

followed by L.

to finish.

Altitude Display

When the GPS 120XL is acquiring satellites or navi­gating in the 2D mode, the last known altitude will be
used to compute your position. If the altitude shown is
off by several hundred feet, you can manually enter
your altitude for greater accuracy. Note that GPS alti­tudes can fluxuate due to errors.

1. Press the Dkey until the altitude field is highlighted
and press

2. Use the arrow keypad to enter the altitude and press

.

F

F

.

Marking and Saving Waypoints

Knowing your present position is only part of any
navigation equation. You also need to keep track of
where you’ve been and where you are going.
Waypoints serve as electronic markers that let you keep
track of starting points, destinations, navaids and any
other important position.

The GPS 120XL allows you to mark, store and use
up to 250 waypoints. A waypoint position can be
entered by taking an instant electronic fix or by manu­ally entering a coordinate or range and bearing in refer­ence to an existing waypoint. If you try to mark a way­point without having a position fix, you’ll be notified
with a ‘No GPS Position’ message.

To mark your present position:

1. Press the Mkey to capture your position.

The mark position page will appear, showing the
captured position and a default 3-digit waypoint name.

To change the default position name:

1. Press the Ukey twice to move the field highlight
from the ‘save’ field to the name field.

2. Press

L

to begin entry of the name. Pressing the

F

key will clear any existing data.

REFERENCE

Marking &

Saving

Waypoints

The GPS 120XL will auto­matically name new way­points with a default three­digit name. You may then
highlight the name field,
press ENTER, and enter
your own waypoint name.

3. Use the arrow keypad to enter the name.

4. Press
highlight will move to the ‘route’ field.

If you’d like to add this waypoint to a route:

1. Press the Fkey.

2. Use the
and press

3. Press the

If you do not want to add this waypoint to a
route:

1. Highlight the ‘save’ field and press the Fkey.

to confirm the waypoint name. The field

F

or Dkeys to enter a route number

U

.

F

key again to save the waypoint.

F

To add a waypoint to a
route as you are marking its
position, enter the desired
route number, highlight
‘SAVE?’ and press ENTER.

19

REFERENCE

Nearest

Waypoints Page

Waypoint Submenus

The GPS 120XL has three waypoint submenu pages
that let you manage a large number of waypoints quick­ly and efficiently. The nearest waypoints, waypoint list
and waypoint definition pages are accessed through the
Menu Page.

To select a waypoint submenu page:

1. Press Jor Quntil the Menu Page appears.

To select a waypoint sub­menu, highlight the desired
option and press ENTER.

The compass heading
(BRG) and distance (DST)
to the nine nearest way­points are updated continu­ously.

2. Use the
submenu page you want to use.

3. Press

4. To return to the Menu Page, press the

and Dkeys to highlight the waypoint

U

to display the submenu page.

F

J

key.

Nearest Waypoints Page

The nearest waypoints page shows the nine nearest
waypoints that are within 100 miles of your present
position, with the bearing and range noted for each
waypoint. During an emergency, the nearest waypoints
page can give you the closest points of safety in your
area at a glance.

The nearest waypoints page will also let you retrieve
a waypoint definition page or GOTO a selected way­point right from the list.

To review the waypoint definition page of a high-

lighted waypoint from the list:

1. Press the Fkey.

To return to the nearest waypoint page (when the

‘done’ field is highlighted):

1. Press the Fkey.

To go to a highlighted list waypoint:

1. Use the Uand Dkeys to highlight a listed way­point.

20

2. To select a highlighted nearest waypoint as a destina­tion, press the

3. Once the GOTO waypoint page appears, press the

key to confirm the selected waypoint as your

F

destination.

G

key.

Waypoint List Page

The waypoint list page provides you with a com­plete list of all waypoints currently stored in the GPS
120XL. The total number of used and empty waypoints
is indicated above the waypoint list. From the waypoint
list page, you can retrieve a waypoint definition page,
delete all user-defined waypoints, or GOTO a selected
waypoint. If a waypoint is currently used in a route, the
lowest route number will be indicated to the left of the
waypoint name.

To review the waypoint definition page of a high-

lighted list waypoint:

1. Press the Fkey.

To return to the waypoint list page (with the

‘done’ field highlighted):

REFERENCE

Waypoint List

Page

1. Press the Fkey.

To GOTO a list waypoint:

1. Use the Uand Dkeys to scroll through the list
and select a waypoint.

2. To select a highlighted waypoint as a destination,
press the

3. Once the GOTO waypoint page appears, press the

F

destination.

To delete all user-defined waypoints:

1. Use the Uor Dkeys to move the cursor high­light to the ‘delete all waypoints’ field.

2. Press the

key.

G

key to confirm the selected waypoint as your

key.

F

A warning page will appear, asking if you are sure
you want to delete all user-defined waypoints and
routes. If you want to continue and delete:

1. Press the Lkey to highlight the ‘Yes’ field.

2. Press the

3. Press the

If you do not want to delete all waypoints:

1. Press Fwith the ‘no’ field highlighted.

key.

F

key to return to the Menu Page.

Q

The total number of used
and available waypoints is
indicated at the top of the
page. Route waypoints are
indicated by an ‘R__’.
Above, R03 means route 3.

Deleting all user waypoints
will also delete all routes
stored in memory.

21

REFERENCE

Waypoint

Definition Page

Waypoint Definition Page

The last of the three waypoint management pages is
the waypoint definition page. This page lets you create
new waypoints manually, or review and edit existing
waypoints.

Waypoint

Name

Reference
Waypoint

Bearing from

Reference
Waypoint

Position

Coordinates

Waypoint Comment

Distance from

Reference
Waypoint

Use the waypoint definition
page to review, rename, or
delete stored waypoints and
to create new waypoints
manually.

To create a new waypoint
by manually entering coor­dinates or by referencing an
existing waypoint, highlight
the ‘NEW?’ prompt and
press the ENTER key.

22

Function Prompts

To create a new waypoint manually, you’ll need to
know its position coordinates or its distance and bear­ing from an existing waypoint.

To create a waypoint by entering coordinates:

1. If a waypoint is currently displayed in the name field,
highlight ‘NEW?’ and press
key to clear the name field.

2. Use

3. Press

4. Press

5. Use the

6. Press

7. Press the

and Dto enter your waypoint name and

U

use

and Rto move to the next character position.

L

to confirm the waypoint name. The posi-

F

tion field will now become highlighted, with the receiv­er’s last known position shown, if one exists.

to begin entry of the position.

F

and Dkeys to enter your position, and

U

use the
field.

default waypoint comment (UTC date and time of cre­ation) will appear, and the highlight will move to
‘DONE?’.

and Rkeys to move to each character

L

to confirm and save your coordinates. The

F

key to return to the Menu Page.

F

. Then press the

F

L

Reference Waypoints

To create a new waypoint manually without know­ing its position coordinates, you’ll need to enter its
bearing and distance from an existing waypoint. The
GPS 120XL will then calculate the position coordinates
for you.

REFERENCE

Reference

Waypoints

To create a new waypoint by referencing a stored

waypoint:

1. Press Uuntil the ‘NEW?’ field is highlighted.

2. Press

3. Enter the name of your new waypoint.

4. Press the
The position field will now become highlighted, with
the receiver’s last known position shown.

5. Press

6. Press
or leave this field blank to use your present position.

7. Use the arrow keypad to enter the waypoint name.

8. Press the

9. Enter the bearing and distance of your new waypoint
from the reference waypoint. Remember to use the

F

coordinates will be calculated and saved for your
new waypoint.

10. Press the

to return to the Menu Page.

.

F

key to confirm the waypoint name.

F

to move the cursor to the reference field.

D

to begin entry of the reference waypoint

F

key to confirm your entry.

F

key to begin entry and confirm each field. The

key (with the ‘done’ field highlighted)

F

The GPS 120XL’s advanced
waypoint and planning fea­tures allow you to create
new waypoints and practice
navigation without ever
leaving the slip.

If you create a new way­point by entering coordi­nates from a map, you may
want to re-mark the way­point’s exact position once
you get there. To re-define
an existing waypoint’s posi­tion coordinates from the
waypoint definition page,
simply highlight the ‘DST’
field and press ENTER. Use
the LEFT arrow key to set
the distance to 0.00, and
press ENTER to confirm.

The old coordinates will be
replaced by the coordinates
of your present position
(you must have a valid 2D
or 3D position fix).

23

REFERENCE

Editing,Deleting

& Renaming

Waypoints

Editing Existing Waypoints

The waypoint definition page also allows you to
change the name, coordinates, comment or reference
waypoint field for a stored waypoint (Fields shown on
page 22).

To edit the name, coordinates, comment, or refer-

ence waypoint field:

1. Use Uand Dto highlight the field you want to
edit.

The waypoint comment
field will automatically dis­play the date and time of
creation of the waypoint.
You may replace this with a
16-character custom com­ment at any time.

To access the rename func­tion from the waypoint def­inition page, highlight the
‘RENAME?’ prompt and
press ENTER.

2. Press

3. Enter your new data.

4. Press the

to begin entry in the selected field.

F

key to confirm your changes.

F

Waypoint Comments

Each waypoint stored in the GPS 120XL has a user­defined 16-character comment field. The default com­ment is the UTC date and time of the waypoint’s
creation.

To change or add a comment:

1. Use the Uand Dkeys to highlight the comment
field.

2. Press

3. Enter the comment and press the

to begin entry of your comment.

F

F

key to confirm.

Renaming and Deleting Waypoints

24

The rename and delete function fields are located at
the bottom left of the waypoint definition page (you’ll
need to use the Lkey to move the field highlightout of
its standard up-and-down scrolling sequence).

To rename a stored waypoint:

REFERENCE

1. Highlight the ‘RENAME?’ field and press F.

2. Enter the new waypoint name and press

3. Press the

key to confirm your changes.

F

F

.

To delete a stored waypoint:

1. Highlight the ‘DELETE?’ field and press F.

2. Press the

3. Press

key to select the ‘YES’ prompt.

L

to delete the waypoint.

F

Scanning Waypoints

As you manually enter a waypoint’s name, the GPS
120XL’s waypoint scanning feature will automatically
display the first numerical or alphabetical match of the
character you have entered to that point. This helps
eliminate the need to always enter a waypoint’s com­plete name.

To scan waypoints from a waypoint field:

Editing and

Scanning

Waypoints

A warning page will ask you
for confirmation to delete
the selected waypoint.

Note: If a waypoint is part
of a route, it must be
removed before it can be
deleted. (See p 34)

1. Highlight the waypoint name field and press F.

2. Press the

3. Use the
points.

4. If you have more than one waypoint that begins with
the same letter or number, you must use the
move to the next character positions as needed. Only
the first character match is listed for each name.

5. Once you’ve found the desired waypoint, press

key to clear the name field.

L

and Dkeys to scroll through way-

U

R

key to

F

.

Waypoint names will
appear alphabetically
when scanning waypoints.
If two waypoints begin with
the same letter(s) you must
move the cursor to the first
letter they do not have in
common for them to appear.

25

REFERENCE

Starting/Stopping

a GOTO & MOB

Selecting a GOTO Destination

The GPS 120XL provides four ways to navigate to a
destination: GOTO, MOB, TracBack and route naviga­tion. The most basic method of selecting a destination is
the GOTO function, which lets you choose any stored
waypoint as the destination and quickly sets a direct
course from your present position.

To activate the GOTO function:

1. Press the Gkey. The GOTO waypoint list, an alpha­betical list of all available waypoints, will appear.

Select a destination way­point from the GOTO way­point list.

Once the MOB mode has
been activated, steering
guidance will be provided
by the highway or compass
page. Activating another
MOB will replace the previ­ous MOB waypoint.

2. Use the
want to navigate to (it may already be highlighted).

3. Press the
tion of a GOTO destination and return to the previous
page.

and Dkeys to select the waypoint you

U

key to confirm, or Qto stop selec-

F

Once a GOTO waypoint has been activated, the
Compass Page or Highway Page will provide steering
guidance to the destination until either the GOTO is
cancelled or the unit has resumed navigating the active
route (see page 34).

To cancel an active GOTO:

1. Press the Gkey.

2. Use the arrow keypad to move the field highlight to the
‘CANCEL GOTO?’ prompt at the bottom of the page and
press

F

.

Man Overboard Function

The GPS 120XL’s man overboard function (MOB)
lets you simultaneously mark and set a course to a posi­tion for quick response to passing positions (like the
spot where your hat blew overboard).

To activate the MOB mode:

1. Press the Bkey. The GOTO waypoint page will
appear with ‘MOB’ selected as the default destination.

26

2. Press the

key to begin MOB navigation.

F

The GPS 120XL will now guide you to the MOB
waypoint until the MOB GOTO is cancelled (see “to
cancel an active GOTO” above). If you want to save the
MOB waypoint, be sure to rename it, because it will be
overwritten the next time a MOB is executed.

TracBack Navigation

The third method of navigating to a destination is
by using the GARMIN’S patented TracBack feature. The
TracBack function allows you to quickly and easily
retrace your path using the track log automatically
stored in the receiver’s memory. The advantage of the
TracBack feature is to eliminate the need to mark way­points along the way and manually create and activate
a route back to where you began your trip.

The TracBack route is created by reducing your
current track log into a route of up to 30 waypoints,
and activating an inverted route along those points.
Once activated, a TracBack route will lead you back to
the oldest track log point stored in memory, so it’s usu­ally a good idea to clear the existing track log at the
starting point of your current trip (e.g. your car or the
dock) before you get started.

To clear the track log and define a starting point

for a TracBack route:

1. From the Menu Page, highlight ‘TRACK LOG’.

2. Press

to access the track log page.

F

REFERENCE

TracBack

Navigation

Clearing the log before you
get started will define the
position the TracBack func­tion will return you to.

3. Use the

4. Press

5. Use

To activate a TracBack route:

1. From the Menu Page, highlight ‘TRACK LOG’ option.

2. Press

3. Highlight the ‘TRACBACK?’ option and press

key to highlight the ‘CLEAR LOG?’ option.

U

. A confirmation page will appear.

F

to highlight the ‘Yes?’ prompt and press F.

L

to access the track log page.

F

F

.

Once the TracBack function has been activated, the
GPS 120XL will take the track log currently stored in
memory and divide it into segments called legs. Up to
30 temporary waypoints (e.g., ‘T001’) will be created to
mark the most significant features of the track log in
order to duplicate your exact path as closely as possi­ble. A TracBack route from your present position to the
oldest track log point will be created as the active route
(the active route page will appear), and provide steer­ing guidance to each waypoint back to the starting
point of your track log.

Highlight ‘TRACBACK?’
and press ENTER to begin
TracBack navigation.

27

REFERENCE

TracBack

Navigation

The TracBack feature will
navigate your track log
back to the oldest point in
the receiver’s memory.

The track log will be divided
into segments with tempo­rary waypoints to create a
route back to the beginning
of the track log.

28

Tips on Creating and Using the TracBack Feature

The GPS 120XL’s TracBack feature is designed to
help you quickly create and activate a route that follows
your path back to a user-defined starting point. To get
the most out of the TracBack feature, remember the fol­lowing tips:

• Always clear your track log at the exact point that
you want to go back to ( truck, dock, etc.).

• The ‘RECORD’ option on the track log setup page
must be set to the ‘Yes’ position.

• There must be at least two track log points stored
in memory to create a TracBack route.

• If there are not enough available waypoints in
memory to create a TracBack route, you will be
alerted with a ‘waypoint memory full’ message,
and the receiver will use any available waypoints
to create a TracBack route with an emphasis on
the track log closest to the destination (the oldest
track log point in memory).

• If the ‘CRITERIA’ option on the track log setup
page is set to a time interval, the TracBack route
may not follow your exact path (the automatic set­ting will provide the best TracBack route).

• If the receiver is turned off or you lose satellite
coverage during your trip, the TracBack route will
simply draw a straight line between any point
where coverage was lost and where it resumed.

• If the changes of direction and distance of your
track log are very complex, 30 waypoints may not
be enough to accurately mark your exact path.
The receiver will then assign the 30 waypoints to
the most significant points of your track.

• If you want to save a TracBack route, copy route 0
to an open storage route before activating another
TracBack. Activating another TracBack or storage
route will overwrite the existing TracBack route.

• Whenever a TracBack route is activated, tempo­rary waypoints (e.g., ‘T001’) that are not con­tained in routes 1-19 are erased. If there are tem­porary waypoints stored in routes 1-19, the
receiver will create any new temporary waypoints
using the first three-digit number available.

Creating and Navigating Routes

The last form of navigating to a destination with
the GPS 120XL is by creating a user-defined route. The
route navigation feature lets you plan and navigate a
course from one place to another using a set of pre­defined waypoints. Routes are often used when it’s not
practical, safe or possible to navigate a direct course to
a particular destination (e.g., through a body of water
or impassable terrain).

Routes are broken down and navigated in smaller
segments called “legs”. The waypoint you are going to
in a leg is called the “active to” waypoint, and the way­point immediately behind you is called the “active
from” waypoint. The line between the “active to” and
the “active from” waypoint is called the “active leg”.

ä

Waypoint 2

(“active to” waypoint)

“Active Leg”

ä

ä

}

ä

Waypoint 1

(“active from” waypoint)

REFERENCE

Route

Navigation

Whenever you activate a route with the GPS
120XL, it will automatically select the route leg closest
to your position as the active leg. As you pass each
waypoint in the route, the receiver will automatically
sequence and select the next waypoint as the “active to”
waypoint.

29

REFERENCE

Defining a

Route

Route Definition Page

The GPS 120XL lets you create and store up to 20
routes of 30 waypoints each. Routes are created, copied
and edited through the route definition page, which is
accessed through the Menu Page.

To select the route definition page:

1. Press Juntil the Menu Page appears.

If you’re heading out with­out a planned route, the
mark function can be used
to quickly create a route
back to your starting point.

Create a series of waypoints
along the way with the
MARK key and save them
to an open route from the
mark position page. When
you’re ready to head back,
simply activate the route
you created in inverted
order (see page 32).

30

2. Use the
option.

3. Press the
page.

4. To return to the Menu Page, press

Comment

Field

Desired

Track of Leg

Copy Field

and Dkeys to highlight the ‘ROUTES’

U

key to display the route definition

F

.

J

Leg Distance

Total Route

Distance

Function Prompts

Route

Number

The route number field is displayed at the top of the
page, with a 16-character user comment below. If no
user comment is entered, the field will display the first
and last waypoint in the route. The waypoint list in the
middle of the page accepts up to 30 waypoints for each
route, with fields for desired track and distance between
legs. The total distance of the route is indicated below
the waypoint list.

The bottom of the route definition page features
several function fields which let you copy, clear, invert
or activate the displayed route. Routes 1-19 are used as
storage routes, with route 0 always serving as the active
route you are navigating. If you want to save a route
currently in route 0, be sure to copy it to another open
route, as it will be overwritten by the next route
activation.

To create a route from the route definition page:

REFERENCE

1. Highlight the route number field and press F.

2. Enter a route number and press the
firm.

3. Press
that the default [first and last waypoint] comment will
only appear if the comment field is blank.)

4. Enter your comment and press the

5. Highlight the No. 1 waypoint field and press

6. Enter the first waypoint of your route and press

7. Continue entering the rest of your waypoints in order,
using the
entry. The list will automatically scroll down.

8. After you have entered all your waypoints, press

J

to begin entry of a route comment. (Note

F

key to start and confirm each field

F

.

F

F

key to con-

key.

.

F

F

Copying and Clearing Routes

The route definition page is also used to copy a
route to another route number. This feature is useful
when you make changes to the active (or TracBack)
route and want to save the route for future use.

To copy a route:

1. Highlight the route number field and press F.

Creating,

Copying &

Clearing Routes

.

Enter each waypoint in the
order you would like to nav­igate them. If you enter a
waypoint not stored in
memory, you’ll need to
define the position on the
waypoint definition page.

2. Enter the route number to be copied and press

3. Highlight the ‘COPY TO’ field and press

4. Scroll through the available routes and select a desti­nation route number. Only open routes will be avail­able as choices. Press the
route.

5. Press the

key to return to the Menu Page.

J

F

F

key to copy the

.

F

.

To clear a route from memory:

1. Highlight the route number field and press F.

2. Enter the route number and press

3. Select the ‘CLR?’ prompt and press

F

F

.

.

To copy a route, select an
open storage roue and press
the ENTER key. If you select
a route that is already used,
you’ll be alerted with a
‘Roue Full’ Message.

31

REFERENCE

Clearing,

Activating and

Inverting Routes

Clearing Routes (continued)

The clear route warning will appear, asking you to
confirm that you want to remove all waypoints from the
route.

1. Highlight the ‘Yes?’ field with the Lkey.

Clearing a route only
removes the waypoints from
the route selected. The way­points used for the route
will still remain in memory
individually.

2. Press

3. Press

to confirm your action.

F

to return to the Menu Page.

J

Activating and Inverting Routes

After a route has been entered, it can be activated in
its defined sequence or inverted from the route defini­tion page. The process of activating or inverting a stored
route takes a storage route (routes 1-19) and copies it
into the active route (route 0) for navigation.

This system allows you to have an active route that
you may edit during navigation and save as an entirely
new route from the original. You will have to copy the
active route to an unused storage route to save it, since
new route or TracBack activation overwrites route 0.

To activate a route:

1. Select the route definition page and press the
key to activate the route number field.

2. Enter the route number to be activated and press

.

F

3. Move the field highlight to the ‘ACT?’ prompt and press
the

key.

F

F

Inverting a route allows you to navigate route legs in

reverse order without editing the original route.

To activate a route, high­light the ‘ACT?’ prompt and
press ENTER.

32

To activate a route in inverted order:

1. Follow the steps above, but select the ‘INV?’ prompt
and press

F

.

Active Route Page

REFERENCE

Once a route has been activated, the active route
page will appear, displaying the waypoint sequence of
your route with the estimated time enroute (ETE) at
your present speed and distance to each waypoint. As
long as you are navigating an active route, the active
route page will become part of the primary page
sequence of the unit.

The active route page will also allow you to change
the ETE field to display desired track (DTK) or estimat­ed time of arrival (ETA) for each leg. In addition you
can also clear or invert the active route.

To display DTK or ETA for each leg:

1. Highlight the estimated time enroute (ETE) field and
press the

2. Use the
press the

key.

F

or Dkeys to select ‘DTK’ or ‘ETA’ and

U

key.

F

The active route page also allows you to clear (stop
navigating) or invert the active route without using the
route definition page.

To invert a route from the active route page:

1. Press the Ukey once to move the field highlight to
the ‘INVERT?’ prompt.

2. Press the

To clear the active route from the active route
page and stop route navigation:

key to invert the route.

F

Active Route

Page

Whenever you have activat­ed a route, the active route
page will appear in the pri­mary page sequence after
the highway/compass page.

1. Use the Uand Lkeys to select the ‘CLEAR?’
prompt.

2. Press the

key to clear the active route.

F

Editing Routes

Once a route has been created and stored, it can be

edited at any time, even if it is the active route.

To edit a route from the active route page or the
route definition page:

1. Use the Uand Dkeys to select the waypoint
you want to edit and press

F

.

To edit or review a route
waypoints from the active
route page, highlight the
desired waypoint and press
ENTER.

33

REFERENCE

Editing Routes&

On-Route

GOTO’s

Editing Routes (continued)

An on-screen menu of editing choices will appear,
with options for reviewing, inserting, deleting or chang­ing the waypoint field highlighted. Use the

arrow keys to select among the editing choices.

D

Once you’ve selected a waypoint from the route

list, choose a menu function:

U

and

Use the on-screen menu to
select the desired editing
function.

You can skip ahead and
navigate to any route way­point by highlighting the
desired waypoint and press­ing the GOTO key.

1. To review the definition page for the waypoint, high­light the ‘REVIEW?’ prompt and press

2. To add a new waypoint preceding the selected way­point, highlight the ‘INSERT?’ prompt and press

3. To remove the selected waypoint, highlight the
‘REMOVE?’ prompt and press the

4. To replace the selected waypoint with a new way­point, highlight the ‘CHANGE?’ prompt and press

F

F

key.

.

.

F

.

F

Use the route waypoint editing instructions
described earlier for creating a route to complete your
changes. If you are editing the active route (route 0),
copy your new route version to an empty route to save
it, because the active route will be overwritten by a new
route activation.

If you add, delete or change the first or last way­point of a route, the default comment (first and last
waypoint) will automatically be updated.

On-Route GOTOs

At the beginning of this section, we mentioned that
the GPS 120XL will automatically select the route leg
closest to your position as the active leg. This will give
you steering guidance to the desired track of the active
leg. If you would prefer to steer directly to a route way­point, you can perform an “on-route GOTO” from the
active route page.

34

1. Use the Uand Dkeys to highlight the desired
route waypoint and press the

2. Once the GOTO waypoint page appears, press
confirm the on-route GOTO waypoint.

G

key.

F

Note that after you reach the on-route GOTO way­point, the GPS 120XL will automatically resume navi­gating the rest of the route in sequence.

to

User-Defined Navigation Pages

Once you’ve selected a GOTO destination or acti­vated a MOB or route, the GPS 120XL will provide
graphic steering guidance to the destination with one
of two navigation pages:

REFERENCE

Highway &

Compass Pages

• The Highway Page (the default navigation page)
provides a graphic highway that shows your
movement relative to the desired course, with an
emphasis on your crosstrack error (the distance
and direction you are off course). The Highway
Page is well suited for boating and other activities
with higher speeds and straight line courses to a
destination.

• The Compass Page provides a directional pointer
to the destination, with a rotating compass graph­ic to display your direction of travel. The
Compass Page is ideal for activities like trawling
or entering a harbor, and provides better steering
guidance for slow-speed (e.g., walking) travel
with many directional changes.

Both pages provide a digital display of the bearing
and distance to the destination, your current speed and
track over the ground, and course deviation indicator
(CDI). Select the desired navigation page at any time.

To select the Compass or Highway Page:

1. Press Juntil the current navigation page appears.

2. Press
navigation page not currently in use highlighted as
the default.

3. Press

. An on-screen box will appear, with the

F

to switch the navigation screen.

F

To switch the navigation
page to the Compass Page,
press ENTER twice.

To switch the navigation
page to the Highway Page,
press ENTER twice.

35

REFERENCE

Highway Page

Using the Highway Page

The GPS 120XL’s Highway Page also provides graph­ic steering guidance to a destination, with a greater
emphasis on the straight-line desired course and the
distance and direction you are off course. The bearing
and distance to a waypoint, along with your current
track and speed are displayed at the top of the screen,
with your estimated time enroute (ETE) and velocity
made good (VMG, or the rate you are closing in on
your destination) at the bottom.

In this example, the
Highway Page indicates
that you are off course to
the right. Steer left to get
back on course. Notice the
emphasis of the Highway
Page is on the desired
course.

If you get too far off course,
a message box will appear
to indicate what course to
steer to get back on course
most efficiently.

36

Bearing to
Waypoint

Track Over

Ground

Destination

Waypoint

Graphic

Highway

Estimated

Time Enroute

Pointer to Waypoint

Distance to

Waypoint

Speed Over

Ground

CDI

Velocity

Made Good

As you head toward your destination, the middle
section of the screen provides visual guidance to your
waypoint on a moving graphic “highway”. The moving
arrow just below the course deviation scale always
points to your selected waypoint relative to the direc­tion you are moving.

Your present position is represented by the diamond
in the center of the course deviation scale. The line
down the middle of the highway represents your
desired track. As you navigate toward a waypoint, the
highway will actually move, indicating the direction
you’re off course, relative to the position diamond on
the CDI scale. To stay on course, simply steer toward
the center of the highway.

If you do get off the desired course by more than
1/5th of the selected CDI range, the exact distance you
are off course will be displayed where the CDI scale set­ting normally appears (see the example at left). If you
get too far off course (the highway has disappeared), a
message box will appear to indicate what course to steer
to get back on course.

Using the Compass Page

The GPS 120XL’s Compass Page provides graphic
steering guidance to a destination waypoint. The bear­ing (BRG) and distance (DST) to the waypoint are dis­played at the top of the page, right below the destina­tion waypoint field. The distance displayed is always
the straight-line distance from your present position to
the destination waypoint. The bearing indicates the
exact compass heading from you to the destination.

REFERENCE

Compass Page

Bearing to

Waypoint

Graphic

Compass

Pointer to
Waypoint

Track Over

Ground

Destination

Waypoint

Distance to

Waypoint

Speed Over

Ground

The middle of the page features a rotating “compass”
that shows your current cardinal heading while you’re
moving (track up), with a pointer arrow in the center to
indicate the direction of the destination relative to the
direction you are moving. The compass rose and pointer
arrow combine to show current direction and current
destination at a glance.

The bottom of the Compass Page shows your current
track (TRK) and speed (SPD) over the ground.

When you are one minute away from the destination
(based on your current speed and track over the ground),
the GPS 120XL will alert you with a flashing on-screen
message box.

In this example, the
Compass Page indicates
that you are traveling in an
easterly (088 degrees)
direction and the destina­tion waypoint is northeast
(058 degrees) of your cur­rent direction of travel.

In this example, the
Compass Page indicates
that you are traveling in a
northerly (031 degrees) and
the destination waypoint is
east (057 degrees) of your
current direction of travel.

37

REFERENCE

Map Page

Map Page

The GPS 120XL features a powerful real-time mov­ing map that can do much more than just plot your
course and route. The Map Page also provides you with
a target cursor that will let you pan ahead to nearby
waypoints, determine the distance and bearing to any
map position, and mark new waypoints while you
navigate.

The GPS 120XL has on­screen range rings to help
you estimate distances rela­tive to your present posi­tion. The value of each ring
is determined by the current
zoom scale, and is equal to
1/5 of the selected scale.

To turn the range rings dis­play on or off (the default
setting is OFF) see the map
setup instructions on pages
51-52.

38

Bearing to
Waypoint

Track Over

Ground

Distance to

Waypoint

Present

Position

Speed Over

Ground

The map contains 12 selectable range scales from

0.2 to 320 miles (0.5 to 600 km). The scale represents
the distance shown from the top of the screen to the
bottom. Move from scale to scale by using the dedicated
zoom keys (IN and OUT). Pressing IN decreases the
scale and pressing OUT increases the scale.

A diamond icon in the center of the page represents
your present position, with your track and/or route dis­played as a solid line. Nearby waypoints are shown as
squares, with the corresponding name listed. You may
select which items are shown through the map setup
submenu page (see pages 51-52 for more information).

The four corners of the Map Page are used to dis­play various navigation data, including the bearing and
distance to a destination waypoint and your current
track and speed over the ground. The two fields at the
top corners of the map show your bearing and distance
to one of three selectable destinations: an active destina­tion waypoint; a highlighted on-screen waypoint; or the
panning target crosshair. If you are not navigating to a
waypoint or using the panning function, the top data
fields will not be displayed. The bottom corners of the
display always show your current track and speed.

Zooming, Panning, and Pointing

There are three main functions you can perform
from the Map Page: zooming, panning, and pointing.
Zooming is increasing or decreasing the display scale of
the map. Panning is using a target crosshair and the
arrow keypad to “slide” the map window in any direc­tion, including diagonally, to view the surrounding
area. Pointing is the act of highlighting a waypoint on
the map in order to find out more about the waypoint
and conduct a GOTO, or highlighting a position on the
map to create a new waypoint and conduct a GOTO.

To select a zoom scale (even while panning):

1. Press Ior Honce for each level of increase or
decrease desired.

2. Press and hold down either key to increase or
decrease by more than one scale.

To activate the pan function:

1. Press the arrow keypad in any direction, including
diagonally.

As you begin to move the map, a crosshair will
appear. This crosshair will now serve as a target marker
for the moving map. The distance and bearing from
your present position to the target crosshair will appear
in the upper corners of the map. If you are conducting
a GOTO at the time you activate the panning function,
the crosshair bearing and distance will replace the bear­ing and distance of the GOTO waypoint.

As you pan around the map, you’ll notice that the
target crosshair will point to on-screen waypoints and
highlight the waypoint name. Once a waypoint name is
highlighted, you can review its waypoint definition
page or execute a GOTO function right from the Map
Page.

To review the definition page for a waypoint

highlighted on the map:

1. Press F. The waypoint definition page will appear.
Review and make any desired changes to the high­lighted waypoint.

REFERENCE

Map Zooming,

Panning, &

Pointing

To change the map scale,
press the IN or OUT key
once for each level desired.
An on-screen window will
display the current zoom
scale.

The crosshair will “snap” to
waypoints highlighted on
the map, which allows you
to quickly review or GOTO
the selected waypoint right
from the Map Page.

2. When finished, highlight the ‘DONE?’ field and press

.

F

39

REFERENCE

Using the

Cursor on the

Map

To mark a waypoint with
the crosshair, simply pan to
the desired position and
press the ENTER key.

Zooming, Panning, & Pointing (continued

To go to a waypoint highlighted on the map:

1. Press the Gkey.The GOTO waypoint page will
appear with the waypoint’s name highlighted.

2. Press the

To stop the panning function and display your
present position:

1. Press the Qkey.

key to confirm.

F

Using the Cursor to Mark and GOTO Waypoints

During panning, the crosshair represents a target
position right on the moving map, with the range and
bearing to the target displayed at the top corners of the
screen.

To mark the target crosshair position as a new

waypoint:

The crosshair may also be
used to define a GOTO des­tination by panning to the
desired position and press­ing the GOTO key. To save
the MAP waypoint, rename
it, as it will be overwritten
by the next MAP waypoint.

40

1. Press the Fkey to capture the position.

2. Enter a new name and route number and press

F

.

You can also use the target crosshair as an instant
GOTO destination. This function will mark and instant­ly set a course for a new waypoint called ‘MAP’.

To GOTO the target crosshair:

1. Press the Gkey to capture the position.

2. Press the

key to confirm the MAP GOTO.

F

To save the MAP waypoint,rename it, as it will be
overwritten the next time a map GOTO is executed.

Menu Page

The GPS 120XL Menu Page provides access to sub­menu pages that are used to select and customize oper­ation and navigation setup. The 11 submenus are
divided into categories by function. See pages 19-34 for
a discussion of waypoint and route management sub­menus. We’ll now address the rest of the submenus in
the order they appear on the Menu Page.

To select a submenu page from the Menu Page:

1. Highlight the submenu page you want to view.

REFERENCE

Menu Page &

Distance/Sun

Calculation

2. Press the

3. To return to the Menu Page, press the

key to display the submenu page.

F

Q

key.

Distance and Sun Calculation

The distance and sun calculation page will give you
the distance and bearing between any two waypoints
and will calculate the sunrise and sunset (in local time)
at a destination waypoint for a particular date.

To perform a distance and sun calculation:

1. Highlight the ‘from’ field and enter the desired way­point. Press

2. Highlight the ‘to’ field and enter the destination way­point. Press the
bearing to the destination waypoint.

3. Highlight the ‘date’ field and enter the date for your
destination. Press the
information.

to move to the next field.

F

key to calculate the range and

F

key to display the sun

F

Message Page

The message page is used to display all messages in
the GPS 120XL. There are two types of messages: tem­porary alerts (e.g. approaching a waypoint) and condi­tion alerts (e.g., battery power is low). All messages are
indicated by a flashing on-screen box. After a tempo­rary alert has been viewed, it is cleared. Condition
alerts are displayed on the message page until the con­dition has been resolved.

To view the message page:

To select a submenu, use the
UP and DOWN arrow keys
to highlight a menu option
and press ENTER.

The GPS 120XL will calcu­late the sunrise and sunset
times of any stored way­point or your present posi­tion. To calculate, enter the
date and year and press
ENTER.

1. Highlight the ‘MESSAGES’ field and press F.

See Appendix C for a complete list of messages.

41

REFERENCE

Track Log Setup

Track Log Setup Page

The track log setup page lets you manage the GPS
120XL’s tracking data. From this page, you can select
whether or not to record a track and define how it is
recorded. Note: Track display options (showing or not
showing a recorded track log on the Map Page). are
addressed on page 52.

To turn track log recording on or off:

1. Highlight the ‘RECORD’ field and press F.

Turning the track recording
option off will prevent you
from using the TracBack
option.

Entering a time interval in
to the track recording crite­ria will plot your position
points further apart than
they would be in the
“Automatic” setting. This
will increase the distance
you can travel without
using up your track log, but
will greatly reduce the effec­tiveness of TracBack.

2. Select ‘Yes’ or ‘No’ and press
track recording off will disable the TracBack feature.

. NOTE: Turning the

F

Track Criteria

The stored track criteria determines how often posi­tions are stored in the track log. The default setting is
automatic, which will store a track based on resolution.
This setting gives you the most efficient use of track
memory and provides the most accurate TracBack route.

To change the criteria to record points based

upon a specific time interval:

1. Highlight the ‘CRITERIA’ field and press F.

2. Use

3. Press

4. Enter a value in hours, minutes and seconds, and

or Dto select ‘Time Interval’ and press

U

.

F

to begin entry of the interval.

F

press the

F

key.

Managing and Clearing the Track Log

The rest of the track log setup page displays the per­centage of available memory currently used to store
track log data and function fields in order to clear the
track log memory and activate the TracBack feature.

To clear the track log:

1. Highlight ‘CLEAR LOG?’ and press F.

2. A warning page will appear, and ask you to confirm
your actions. Use the
to the ‘Yes?’ field and press

key to move the field highlight

L

F

.

42

TracBack Function

The TracBack option lets you activate a TracBack
route using the track log (see pages 29-30 for more
information).

To activate a TracBack route:

1. Highlight the ‘TRACBACK?’ option and press F.

Interface Setup

The interface setup page lets you specify the inter­facing formats for connecting external devices. There
are five interface options: GRMN/GRMN, None/None,
None/NMEA, RTCM/None, and RTCM/NMEA. Each
option lists the input format first, followed by the out­put format.

To select I/O format:

REFERENCE

TracBack &

Interface

Options

1. Highlight the I/O field and press F.

2. Use the
select the desired setting, and press

and Dkeys to toggle through and

U

F

.

The GRMN/GRMN setting is a proprietary format
that lets you exchange information such as waypoints,
routes and track logs between two GARMIN GPS
devices or a PC. During data transfer, the number of
packets being exchanged will be displayed on screen.

To select a transfer option:

1. Highlight the ‘host’ field and press F.

2. Use

and Dto select a setting and press F.

U

A field for additional infor­mation will be displayed
when required for the select­ed interface option. Above,
the None/NMEA option will
allow input of NMEA ver­sions and a baud rate.

Chose a ‘HOST’ field based
upon the type of informa­tion transfer you want to
occur between the two
interfacing devices.

43

REFERENCE

DGPS Interface

The ‘NONE/NMEA?’ set­ting makes it possible to
output data to output infor­mation to devices like chart­plotters and autopilots.

To disable all interfacing capabilities, select the
None/None setting. If you want to output NMEA data
to compatible external devices without any differential
input capability, select the None/NMEA setting. Once a
NMEA output setting has been selected (with or with­out RTCM input), the NMEA field will become high­lighted. NMEA formats 0180, 0182 or 0183 (1.5 or 2.0)
are available.

To select a NMEA format:

1. Press Fto begin a NMEA selection.

The selectable baud rate is
available for all RTCM
interface options.

44

2. Use

and Dto select a format, and press F.

U

DGPS Interface

The last two format settings allow the differential­ready GPS 120XL to accept RTCM DGPS corrections in
RTCM 104 version 2.0 format. Using DGPS corrections
will improve receiver accuracy to 5-10 meters, regard­less of errors induced by the U.S. government’s Selective
Availability (SA) program. The RTCM/NONE format
will allow connection to any manually tuned beacon
receiver by using the proper output interface. The baud
rate is selectable from the GPS 120XL.

The RTCM/NMEA selection controls the GARMIN
GBR-21 differential beacon receiver. Once a RTCM set­ting has been selected, the GPS 120XL will either auto­matically try to tune the last frequency and bit rate you
selected or will switch to the default frequency of 304.0
kHz with a bit rate of 100 bps if no previous beacon
has been tuned. You may also enter your own frequency
and bit rate if desired.

DGPS Interface (continued)

To enter a DGPS beacon frequency:

1. Highlight the ‘freq’ field and press F.

2. Enter the desired frequency and press

F

REFERENCE

DGPS Interface

& System Setup

.

3. Highlight the ‘rate’ field and press

4. Use

5. Press the

and Dto select the desired transmission

U

rate.

key to confirm your entry.

F

F

.

When the GPS 120XL is receiving DGPS correc­tions from the GBR-21, the ‘beacon receiver’ section of
the I/O setup page will display the beacon frequency
and signal strength, as well as the distance from the
transmitter to the beacon receiver. At the bottom of the
beacon receiver field, a status message will keep you
informed of DGPS activity:

• A ‘Tuning’ message will be displayed while a bea­con signal is being tuned.

• Once the beacon signal has been tuned, a
‘Receiving’ message will be displayed.

• If a beacon signal is tuned and no corrections are
being received, a ‘No Data’ message will be dis­played.

• If a beacon signal cannot be tuned, a ‘No Status’
message will be displayed.

The GPS 120XL will also display one of three alert
messages concerning DGPS operation through the mes­sage page:

No DGPS Position— not enough data is available

to compute a DGPS position.
No RTCM Input— the beacon receiver is not

properly connected or the baud rates do not
match.

RTCM Input Failed— DGPS data was being
received but has been lost.

Once a RTCM option is
selected, you must manual­ly tune the beacon receiver
from the frequency field.

Alert messages will signal
any problems with DGPS
operation.

45

REFERENCE

Setting Time,

Screen Contrast,

& Tone

The GPS 120XL’s two oper­ating modes are accessed
through the system setup
submenu.

System Setup

The next setup page is the system setup page, which
is used to select the operating mode, time offset and
screen preferences. The GPS 120XL has two operating
modes:

• ’Normal’ Mode operates the unit at maximum
performance, and provides a battery of life up to
12 hours on alkaline batteries.

• ’Simulator’ Mode allows you to operate the unit
without acquiring satellites, and is ideal for prac­ticing or entering waypoints and routes while at
home.

To select an operating mode:

To display the correct local
time, you must enter the
appropriate offset from the
chart at the end of
Appendix C.

46

1. Highlight the ‘MODE’ field and press F.

2. Use the arrow keypad to select a mode and press
.

F

Date and Time Setup

The date and time field is located directly below the
mode field. Because the time shown is UTC time, you
will need to enter a time offset to display the correct
local time for your area. To determine the time offset for
your area, note your position and refer to the chart in
Appendix C.

To enter the time offset:

1. Highlight the ‘OFFSET’ field and press the Fkey.

2. Enter the time offset and press
select a positive or negative indicator for your offset.

. Remember to

F

Time Format

The time display shown on the system setup and
Position Pages may be set to display the time in a 12 or
24-hour format.

To select the time format:

1. Highlight the ‘HOURS’ field and press the Fkey.

REFERENCE

Navigation

Setup

2. Select 12-or 24-hour display, and press
confirm.

F

to

Screen Contrast

The GPS 120XL features adjustable screen contrast

and is controlled by using an on-screen bar scale.

To set the screen contrast:

1. Move the field highlight to the ‘CONTRAST’ field and
press the

2. Use the
desired contrast and press the

key.

F

and Rkeys to adjust the bar scale for the

L

F

key.

Tone Setting

Choose 24-hour (military)
or 12-hour time display
from the ‘HOURS’ field.

You may choose from three settings for audible
tone: messages only, messages and keystrokes, or no
tone at all.

To specify a tone setting:

1. Highlight the ‘TONE’ field and press the Fkey.

2. Use the
and press

and Dkeys to select the desired tone

U

.

F

Screen contrast may be
adjusted to your lighting
conditions with the contrast
bar.

47

REFERENCE

Navigation

Setup

The position format may be
set to display your choice of
many formats. Note: degree
and minutes is the default
setting..

Navigation Setup

The navigation setup page is used to select units of
measurement for position format, map datum, CDI
scale, and distance, speed and heading information.

Position Formats

The default position setting for the GPS 120XL is
latitude and longitude in degrees and minutes
(hdddºmm.mmm’). You may also select degrees, min­utes and seconds (hdddºmm’ss.s’’); degrees only
(hddd.dddddº); UTM/UPS coordinates; or British,
German, Irish, Maidenhead, Swedish, Swiss or Taiwan
grid formats.

To select a position format:

Use any of the 106 separate
map datums to maximize
the operation of the GPS
120XL with your specific
map or chart.

48

1. Highlight the ‘POSITION FRMT’ field and press F.

2. Use the
ting. Confirm the setting by pressing

and Dkeys to select the desired set-

U

F

.

Map Datums

The map datum field is located just below the posi­tion format field, and comes with a WGS 84 default set­ting. Although 104 total map datums are available for
use (see the map datum listing in appendix B), you
should only change the datum if you are using maps or
charts that specify a different datum than WGS 84.

To select a map datum:

1. Highlight the ‘MAP DATUM’ field and press F.

2. Use the
select the desired setting. Confirm the setting by
pressing

and Dkeys to toggle through and

U

.

F

CDI Scale Settings

The course deviation indicator (CDI) scale defini­tion field lets you select the +/- range of the CDI bar
scale on the Highway Page. Three scales are available:
+/- 0.25, 1.25 and 5.0 miles or kilometers, with 0.25
being the default setting.

To enter a CDI scale setting:

1. Highlight the ‘CDI SCALE’ field and press F.

REFERENCE

Units of

Measure &

Speed Filter

2. Use the
ting.

3. Press the

and Dkeys to select the desired set-

U

key to confirm the selection.

F

Units of Measure

The GPS 120XL lets you select nautical (default),
statute or metric units of measure for all speed and dis­tance fields.

To change the unit of measure:

1. Highlight the ‘units’ field and press the Fkey.

2. Use

3. Press the

and Dto select the desired unit of

U

measure.

key to confirm the selection.

F

Speed Filter

Adjusting the CDI Scale will
determine the value used in
the Highway Page and for
the range rings on the Map
Page (if displayed).

Choose a navigation unit
you are familiar with or
that may be appropriate to
the situation in which the
GPS 120XL is used.

49

REFERENCE

Speed Filter &

Magnetic

Heading

Speed Filter (continued)

The speed filter allows you to determine how the
GPS 120XL responds to changes in track or ground
speed. Three settings are available: automatic, on, or off.
The ‘Auto’ setting is the default and will monitor the
changes in your current track and speed and adjust the
receiver’s response time automatically. The ‘On’ setting
allows you to manually enter a response time up to 300
seconds. Selecting a higher setting may be desirable in
slow-speed applications with frequent changes in track.

To enter a value for the speed filter:

1. Highlight the ‘SPEED FILTER’ field and press F.

Setting the speed filter to
‘On’ makes it possible for
you to select the receiver’s
time response to changes in
track or ground speed.

The number entered repre­sents a window of time the
GPS 125 Sounder considers
in adjusting to changes in
speed and track. For exam­ple, if 12 seconds is entered,
the speed displayed will
constantly represent the
speed averaged over the last
12 seconds.

2. Select the ‘ON’ option and press

3. Highlight the “speed value” field and press the
key.

4. Use

5. Press the

and Dto select the desired number of

U

seconds.

key to confirm the selection.

F

F

.

F

Magnetic Heading Reference

The GPS 120XL’s heading information can be dis­played referencing magnetic north (auto or user­defined), true north or calculated grid headings. The
default setting is automatic magnetic north, which is
suitable for most applications.

50

Magnetic Heading Reference (continued)

To select a heading reference:

1. Highlight the ‘HEADING’ field and press F.

2. Select the desired heading preference.

REFERENCE

Magnetic

Heading & Map

Setup

3. Press the

To enter a user-defined magnetic heading

. 1. Select the ‘USER MAG’ option and press F.

2. Use the
and direction of magnetic variation.

3. Press the
variation value.

key to confirm the selection.

F

and Dkeys to enter the degrees

U

key to confirm the magnetic

F

:

Map Setup and Orientation

The map setup page lets you select map orientation
and specify what items are displayed. The map may be
oriented to north up, the direction of current travel
(track up) or the direction of an active route leg
(desired track up). The default setting is track up.

To change the map orientation:

1. Highlight the ‘ORIENTATION’ field and press F.

2. Use the
select the desired setting, and press

and Dkeys to toggle through and

U

F

.

Selecting Displayed Items on the Map Page

The rest of the map setup page lets you specify
what items are displayed or plotted on the Map Page.
The first four plot items may be turned on or off by
selecting ‘yes’ or ‘no’ in the appropriate field:

• The ‘RINGS’ selection will display the three pre­sent position range rings on the map.

• The ‘ROUTE’ selection will plot the straight leg
lines between waypoints of an active route and
display all route waypoint names.

To enter a user-defined
magnetic variation, select
the ‘User Mag’ option and
enter the desired direction
and value.

The ‘North Up” orientation
causes the top-center of the
Map Page to represent
000º, the right-center to be
090º, the bottom-center
180º, and the left-center to
be 270º.

51

REFERENCE

Map Page Setup

& Track Log

Display

Selecting Displayed Items on the Map Page (cont.)

• The ‘NEAREST’ selection will display the nine
nearest waypoints to your present position (not to
the target cursor on the map).

• The ‘NAMES’ selection will display the waypoint
name for the nine nearest waypoints.

To turn a plotted item on or off:

1. Highlight the confirmation (Yes or No) field for the plot­ted item and press

F

.

On-screen range rings will
appear on the map when
the ‘RINGS’ option is set to
the ‘Yes’ position.

The screen resolution of the
track log may be changed
by increasing the number of
tracklog points displayed.
However, displaying too
many points may clutter
your screen .

2. Use

or Dto select ‘Yes’/‘No’, and press F.

U

Track Log Display

The track log option sets the number of points the
unit will attempt to display on the Map Page. The
default setting of 250 points provides good resolution
with minimal screen clutter. The maximum setting is
768 points. Once the maximum number of track points
is reached, the older points will be lost as new points
are added. Note that adjusting the points displayed will
not affect whether or not the receiver records a track log
or the ability to create a TracBack route.

To enter a log setting:

1. Highlight to the ‘track log’ field and press F.

2. Enter a value in the 3-digit field and press
do not want to display a track, enter ‘000’.

F

. If you

52

Alarms Setup

The alarms setup page is used to set the three
alarms available on the GPS 120XL: the anchor drag
alarm, arrival alarm, and CDI alarm.

The anchor drag alarm will sound if your boat has
moved outside a range measured from a central point
(your position). The arrival alarm sounds when you are
approaching a waypoint and have reached the user
defined distance. The CDI alarm will alert you when
your track varies from the shortest distance to a way­point by the defined range.

The arrival and CDI alarms may be set from 0.0 to

9.9 units. The anchor drag alarm may be set up to 9.99
distance units.

To set the alarms:

REFERENCE

Alarms Setup

When activated, the arrival
alarm will sound when you
reach the specified distance
from your destination
waypoint.

1. Move the highlight to ‘ALARMS SETUP’ and press
.

F

2. Select the desired alarm distance field and press

.

F

3. Enter the distance for the alarm and press

4. If you would like to change the ‘On/Off’ setting, press

the

key and use the Uand Dkeys to turn

F

the alarm on or off.

5. Enter a setting and press the

When setting the anchor drag alarm, remem-

!

#

ber that Selective Availability can degrade
your GPS position as much as 100 meters and
may cause false anchor drag alerts.

F

F

key.

.

Use the CDI alarm to
ensure you maintain a
straight-line course to the
destination waypoint.

53

REFERENCE

Nav Simulator

Navigation Simulator

The GPS 120XL’s simulator mode lets you practice
all aspects of its operation without active satellite acqui­sition. You can also plan and practice trips, enter new
waypoints and routes, and save them for use during
normal operation. The simulator is activated from the
system setup page, with speed and heading controlled
from the Position, Compass or Highway Pages.

To activate the simulator:

1. Highlight ‘SYSTEM SETUP’ and press F.

Select the simulator mode
from the operation mode
choices and press ENTER.
You may return to normal
operation by changing the
operation mode or by turn­ing the unit off.

2. Highlight the ‘MODE’ field and press

3. Use

4. Press

or Dto select the simulator mode and press

U

.

F

to return to the Menu Page.

F

F

.

Once the simulator mode has been activated, use
the Position, Compass or Highway Page to set your
speed and track. You may also enter a new position if
you desire (only from the Position Page).

To enter track, speed and position:

1. Highlight the ‘TRACK’ field and press the Fkey.

2. Enter a track heading and press

3. Highlight the ‘SPEED’ field and press

4. Enter a speed and press

5. Highlight the ‘POSITION’ field (Position Page only) and
press

6. Enter a position and press the

The GPS 120XL does not track satellites in sim-

!

#

ulator mode. Although you can create and save
waypoints and routes while using the simulator
mode, never attempt to use the simulator mode
for actual navigation.

F

.

F

.

F

F

.

F

key.

.

54

Installation

The GPS 120 XL must be properly installed accord­ing to the following instructions to get the best possible
performance.

To complete the standard installation, you will need
the following pieces:

• 1 amp in-line fuse (may be included with
Power/Datacable)

• Four 1/4” (6mm) diameter mounting screws

• 1” x 14 marine antenna mount and screws

Several optional accessories are also available to
provide flexible installation on any vessel. See your
GARMIN dealer for more information on these items:

• AC Adapter

• Antenna Cable Extension

• Cigarette Lighter Adapter

To begin installation, you’ll need to select a suitable
mounting position for the antenna and the unit. Once
you’ve identified the best mounting location, install the
antenna and cable first, then the unit and wiring
harness.

Mounting the GPS antenna

The antenna should be mounted in a location that
has a clear, unobstructed view of the sky in all direc­tions to ensure the best reception in all conditions.
Avoid mounting the antenna where it will be shaded by
the boat’s superstructure, a radome antenna, or mast.
Most marine VHF and loran antennas will not seriously
degrade the GPS antenna’s reception. Never paint the
antenna or clean it with harsh solvents.

To install the GPS antenna:

APPENDIX A

Installation

1. Screw the antenna directly onto the 1” – 14 mount.

2. Route the cable to the location of the display unit, using
the appropriate tie-wraps,escutcheon plates and sealant
to secure the cable along the route and through any
bulkhead or deck.

3. Once the GPS 120XL unit has been installed, connect the
cable to the antenna connector on the back of the dis­play unit. Turn the antenna connector 1/4 turn clockwise
to lock the cable into place.

55

APPENDIX A

Installation

Mounting the GPS 120XL

The GARMIN GPS 120XL’s compact case is suitable
for mounting in exposed locations or at the nav station.
The unit comes with a gimbal bracket that can be used
for surface, overhead, or flush mounting. When choos­ing a location for the display unit, make sure you con­sider the following conditions:

• There should be at least 2.00” (5.0 cm) clearance
behind the case to allow connection of the anten­na and power/data cables.

• The mounting surface should be rigid enough to
support the unit and protect it from excessive
vibration and shock.

To surface mount the GPS 120XL:

56

1. Place the mounting bracket in the desired location.

2. Mark and drill the four mounting holes for the fasten-

ers you are using.

3. Fasten the bracket to the surface using the appropri-

ate fasteners.

4. Insert the GPS 120XL into the mounting bracket.

5. Screw the two mounting knobs through the bracket

and into the GPS 120XL.

6. Connect the power/data and antenna cables to the

back of the unit, making sure the locking rings are
fully tightened on both connectors.

To flush mount the GPS 120XL:

The GPS 120XL can be mounted flush with a flat
panel of .08-.52” thickness using the cam lobe feature
on its mounting bracket.

1. Cut a 4.15” W x 4.67” H hole in panel.

2. Place GPS 120XL into hole from the front until its
flange rests against the mounting surface.

3. From the back side of the panel, loosely attach the
bracket such that the slot in the ratchet area points
away from the mounting panel.

APPENDIX A

Installation

4. Rotate the bracket downward until the panel
is pinched tightly between the units flange
and bracket lobe.

5. Tighten knobs and connect the power/data
and antenna cables. Note: If the panel is too thick to
allow use of the knobs supplied, use two M6 screws
to secure the bracket.

57

APPENDIX B

PIN 1 (red): 10-40 volts DC

PIN 2 (black): Ground

PIN 3 (blue): NMEA out

PIN 4 (brown): NMEA in

PIN 5 (white): No connection

PIN 6 (green): No connection

PIN 7 (yellow): alarm low

1

2

3

4

5

6

7

Pin assignment

(-) (+)

10-40 volts DC

Autopilot/

NMEA Device

GBR 21
Beacon

Receiver

Alarm/

Relay

(-)

Shield Grounded

Through GPS

(+)

Connecting the power/data cable

The power/data cable connects the GPS 120XL sys-

Wiring &

Specifications

tem to a 10-40 volt DC power source and provides inter­face capabilities for connecting NMEA devices and an
external alarm The diagram below indicates the appropri­ate harness connections.

To connect the GPS 120XL to a power source:

1. Connect the RED harness lead to the positive side of a 10-40 volt DC power source. Make sure
the power lead has an in-line 1-amp fuse installed.

2. Connect the BLACK harness lead to a ground strip or the negative side of a
10-40 volt DC power source.

To connect an external alarm, connect the ground side of the alarm device to the
YELLOW harness lead. (100 mA DC load max.) The following interface formats are sup­ported by the GPS 120XL for driving three NMEA devices:

NMEA 0180, NMEA 0182,

NMEA 0183 version 1.5:

Approved sentences:

GPBWC, GPGLL, GPRMB, GPRMC, GPXTE,
GPVTG, GPWPL

Proprietary sentences:

PGRMM (map datum), PGRMZ
(altitude), PSLIB (beacon rec. control)

58

NMEA 0183 version 2.0:

Approved sentences:

GPGGA, GPGLL, GPGSA, GPGSV,
GPRMB, GPRMC, GPRTE, GPWPL

Proprietary sentences:

PGRME (estimated error), PGRMM (map
datum), PGRMZ (altitude), PSLIB (beacon
receiver control)

The GPS 120XL is constructed of high quality
materials and should not require user maintenance. Should
your unit ever need repair, please take it to an authorized
GARMIN service center. The GPS 120XL has no user ser­viceable parts. Never attempt any repairs yourself.

To protect your GPS, never allow gasoline or other sol­vents to come in contact with the case or screen. Clean the
case and screen with a soft cloth and a household window
cleaner.

PHYSICAL

Case: Gasketed construction
Size: 4.9”H x 5.3”W x 2.4”D

(15.6 x 5.1 x 1.23 cm)
Weight: Less than 1 lb. (454g)
Temperature Range: 5º to 158ºF (-15º to 70ºC)

PERFORMANCE

Receiver: Differential-ready MultiTrac8
Acquisition Time: Approx. 20 seconds (warm)

Approx. 2 minutes (cold)

Approx. 7.5 minutes (AutoLocate)
Update Rate: 1/second, continuous
Position Accuracy: 5-10 meters (16-33 ft.) with DGPS corrections*

15 meters (49 ft.) RMS**
Velocity Accuracy: 0.1 knot RMS steady state, 99 knots max.
Dynamics: Performs specification to 3g’s

APPENDIX B

Wiring &

Specifications

POWER

Input: 10-40v DC
Usage: 2 watts

Specifications subject to change without notice

* With optional GARMIN GBR 21 Beacon Receiver Input.

** Subject to accuracy degradation to 100m 2DRMS under the U.S. DOD-imposed

Selective Availability Program.

59

APPENDIX C

The GPS 120XL uses a flashing on-screen message to

alert you to important information. Whenever the message

Messages &

Time Offsets

indicator appears, press the PAGE key to view the message
page. There are two types of messages: temporary alerts
and condition alerts. Temporary alerts are cleared from the
message page after viewing, while condition alerts remain
on the message page until the condition has been resolved.
Pay careful attention to all messages for your own safety.

Active WPT Can’t be Deleted—You have attempted to change the “active to” or “active
from” waypoint. Clear the active route or GOTO before making your changes.

Accuracy has been Degraded—The accuracy of the GPS 120XL has been degraded
beyond 500 meters due to poor satellite geometry or data quality. You should check other
navigational sources to verify the position indicated.

Already Exists—The name you are entering already exists in the GPS 120XL’s memory.
Approaching—You are one minute away from reaching a destination waypoint.
Battery Power is Low—The batteries are low and should be replaced.
No DGPS Position—Not enough data is available to compute a DGPS position.

No RTCM Input—
Poor GPS Coverage—The GPS 120XL cannot acquire the necessary number of satellites to

compute a position. Try another location with a clearer view of the sky.
Power Down and Re-init—The GPS 120XL is not able to calculate a position due to

abnormal satellite conditions. Turn the unit off and verify the last position shown by other
means. Try the unit again later, possibly in a different location.

Read Only Mem has Failed—The permanent memory has failed and the unit is not oper­able. Take your unit to an authorized GARMIN dealer for repairs.

Received an Invalid WPT—A waypoint was received during upload transfer that has an
invalid identifier.

Receiver has Failed—A failure in receiver hardware has been detected. If this message
persists, do not use the unit and take it to an authorized dealer for repair.

Route is Full—You have attempted to add more than 30 waypoints to a route.
Route is not Empty—You have attempted to copy into a route already in use.
Route Waypoint Can’t be Deleted—The waypoint you are trying to delete is part of a

route. Delete the waypoint from the route before removing it from memory.
Route Waypoint was Deleted—A route waypoint entered does not exist in the database

and has been deleted from the route.
RTCM Input has Failed—DGPS data being received has been lost. You are no longer

receiving the beacon signal.
Searching the Sky—The GPS 120XL is in searching the sky for almanac data or the unit is

in AutoLocate

Beacon receiver is improperly connected or baud rates do not match.

TM

mode.

60

APPENDIX C

Messages &

Time Offsets

Route Waypoint was Deleted—A route waypoint entered does not exist in the database
and has been deleted from the route.

RTCM Input has Failed—DGPS data being received has been lost. You are no longer
receiving the beacon signal.

Searching the Sky—The GPS 120XL is searching the sky for almanac data or the unit is in
AutoLocate

Stored Data was Lost—All waypoints, routes, time and almanac data have been lost due
to battery failure or clearing the receiver’s memory.

Transfer has been Completed—The receiver is finished uploading or downloading infor­mation to the connected device.

WPT Memory is Full—You have used all 250 waypoints in the GPS 120XL. Delete
unwanted waypoints to make room for new entries.

you are in daylight savings time, add one hour to the offset.

TM

mode.

The chart below gives the UTC time offset for the various longitudinal zones. If

Longitudinal Zone Offset Longitudinal Zone Offset

W180.0º to W172.5º -12 E007.5º to E022.5º 1
W172.5º to W157.5º -11 E022.5º to E037.5º 2
W157.5º to W142.5º -10 E037.5º to E052.5º 3
W142.5º to W127.5º -9 E052.5º to E067.5º 4
W127.5º to W112.5º -8 E067.5º to E082.5º 5
W112.5º to W097.5º -7 E082.5º to E097.5º 6
W097.5º to W082.5º -6 E097.5º to E112.5º 7
W082.5º to W067.5º -5 E112.5º to E127.5º 8
W067.5º to W052.5º -4 E127.5º to E142.5º 9
W052.5º to W037.5º -3 E142.5º to E157.5º 10
W037.5º to W022.5º -2 E157.5º to E172.5º 11
W022.5º to W007.5º -1 E172.5º to E180.0º 12
W007.5º to E007.5º 0

61

APPENDIX D

Map Datums

The following list shows the 104 map datums
available for the GPS 120XL. Menu Page abbrevi­ations are listed first, followed by the correspond­ing map datum name and area.

Adindan Adindan- Ethiopia, Mali,

Senegal, Sudan

Afgooye Afgooye- Somalia
AIN EL ABD ‘70 AIN EL ANBD 1970-

Bahrain Island, Saudi Arabia

Anna 1 Ast ‘65 Anna 1 Astro ‘65- Cocos Isl.
ARC 1950 ARC 1950- Botswana,

Lesotho, Malawi, Swaziland,
Zaire, Zambia, Zimbabwe

ARC 1960 ARC 1960- Kenya, Tanzania
Ascnsn Isld ‘58 Ascension Island ‘58-

Ascension Island

Astro B4 Sorol Astro B4 Sorol Atoll- Tern

Island

Astro Bcn “E” Astro Beacon “E”- Iwo Jima
Astro Dos 71/4 Astro Dos 71/4- St. Helena
Astr Stn ‘52 Astronomic Stn ‘52- Marcus

Island

Astrln Geod ‘66 Australian Geod ‘66-

Australia, Tasmania Island

Astrln Geod ‘84 Australian Geod ‘84-

Australia, Tasmania Island

Bellevue (IGN) Efate and Erromango Islands
Bermuda 1957 Bermuda 1957- Bermuda

Islands

62

Bogata Observ Bogata Obsrvatry- Colombia
Campo Inchspe Campo Inchauspe- Argentina
Canton Ast ‘66 Canton Astro 1966- Phoenix

Islands

Cape Cape- South Africa
Cape Canavrl Cape Canaveral- Florida,

Bahama Islands

Carthage Carthage- Tunisia
CH-1903 CH 1903- Switzerland
Chatham 1971 Chatham 1971- Chatham

Island (New Zealand)

Chua Astro Chua Astro- Paraguay
Corrego Alegr Corrego Alegre- Brazil
Djakarta Djakarta (Batavia)- Sumatra

Island (Indonesia)

Dos 1968 Dos 1968- Gizo Island

(New Georgia Islands)

Easter Isld 67 Easter Island 1967
European 1950 European 1950- Austria,

Belgium, Denmark, Finland,
France, Germany, Gibraltar,
Greece, Italy, Luxembourg,
Netherlands, Norway,
Portugal, Spain, Sweden,
Switzerland

APPENDIX D

Map Datums

European 1979 European 1979- Austria,

Finland, Netherlands,
Norway, Spain, Sweden,
Switzerland

Finland Hayfrd Finland Hayford-

Finland

Gandajika Base Gandajika Base- Republic

of Maldives

Geod Datm ‘49 Geodetic Datum ‘49-

New Zealand

Guam 1963 Guam 1963-

Guam Island

Gux 1 Astro Gux 1 Astro-

Guadalcanal Island

Hjorsey 1955 Hjorsey 1955- Iceland
Hong Kong ‘63 Hong Kong ‘63-

Hong Kong

Hu-Tzu-Shan Hu-Tzu-Shan- Taiwan
Indian Bngldsh Indian- Bangladesh,

India, Nepal

Indian Thailand Indian- Thailand,

Vietnam

Indonesia ‘74 Indonesia 1974-

Indonesia

Ireland 1965 Ireland 1965- Ireland
ISTS 073 Astro ISTS 073 ASTRO ‘69-

Diego Garcia

Johnston Island Johnston Island

Kandawala Kandawala­Sri Lanka

Kerguelen Islnd Kerguelen Island
Kertau 1948 Kertau 1948- West

Malaysia, Singapore

L. C. 5 Astro Cayman Brac Island
Liberia 1964 Liberia 1964- Liberia
Luzon Mindanao Luzon- Mindanao Island
Luzon Philippine Luzon- Philippines

(excluding Mindanao
Island)

Mahe 1971 Mahe 1971- Mahe Island
Marco Astro Marco Astro- Salvage

Island

Massawa Massawa- Eritrea

(Ethiopia)

Merchich Merchich- Morocco
Midway Ast ‘61 Midway Astro ‘61-

Midway

Minna Minna- Nigeria
NAD27 Alaska North American 1927-

Alaska

NAD27 Bahamas North American 1927-

Bahamas (excluding San
Salvador Island)

NAD27 Canada North American 1927-

Canada and
Newfoundland

NAD27 Canal Zone North Am. 1927- Canal

Zone

NAD27 Caribbn North American 1927-

Caribbean (Barbados,
Caicos Islands, Cuba,
Dom. Rep., Grand
Cayman, Jamaica,
Leeward and Turks
Islands)

NAD27 Central North American 1927-

Central America (Belize,
Costa Rica,
El Salvador, Guatemala,
Honduras, Nicaragua)

NAD27 CONUS North Am. 1927- Mean

Value (CONUS)

NAD27 Cuba North American 1927-

Cuba

NAD27 Grnland North American 1927-

Greenland
(HayesPeninsula)

NAD27 Mexico N. American 1927-

Mexico

NAD27 San Sal North American 1927-

San Salvador Island

NAD83 North American 1983-

Alaska, Canada, Central
America, CONUS,
Mexico

63

APPENDIX D

Map Datums

Nhrwn Masirah Nahrwn- Masirah Island

(Oman)

Nhrwn Saudi A Nahrwn- Saudi Arabia
Nhrwn United A Nahrwn- United Arab

Emirates

Naparima BWI Naparima BWI- Trinidad

and Tobago

Obsrvtorio ‘66 Observatorio 1966-

Corvo and Flores Islands
(Azores)

Old Egyptian Old Egyptian- Egypt
Old Hawaiian Old Hawaiian- Mean

Value

Oman Oman- Oman
Ord Srvy GB Old Survey Grt Britn-

England, Isle of Man,
Scotland, Shetland Isl.,
Wales

Pico De Las Nv Canary Islands
Ptcairn Ast ‘67 Pitcairn Astro ‘67-

Pitcairn Isl.

Prov S Am ‘56 Prov So Amricn ‘56-

Bolivia, Chile,Colombia,
Ecuador, Guyana, Peru,
Venezuela

Prov S Chln ‘63 Prov So Chilean ‘63- S.

Chile

Puerto Rico Puerto Rico & Virgin

Islands

Qatar National Qatar National- Qatar
Qornoq Qornoq- South

Greenland

Reunion Reunion- Mascarene

Island

Rome 1940 Rome 1940- Sardinia

Island

RT 90 Sweden
Santo (Dos) Santo (Dos)- Espirito

Santo Island

Sao Braz Sao Braz- Sao Miguel,

Santa Maria Islands
(Azores)

64

Sapper Hill ‘43 Sapper Hill 1943- East

Falkland Island

Schwarzeck Schwarzeck- Namibia

Sth Amrcn ‘69 South American ‘69-

Argentina, Bolivia, Brazil,
Chile, Colombia,
Ecuador, Guyana,
Paraguay, Peru,
Venezuela, Trinidad and
Tobago

South Asia South Asia- Singapore

SE Base Southeast Base- Porto

Santo and Madiera
Islands

SW Base Southwest Base- Faial,

Graciosa, Pico, Sao Jorge
and Terceira Islands
(Azores)

Timbalai 1948 Timbalai 1948- Brunei

and E. Malaysia (Sarawak
and Sabah)

Tokyo Tokyo- Japan, Korea,

Okinawa

Tristan Ast ‘68 Tristan Astro 1968-

Tristan da Cunha

Viti Levu 1916 Viti Levu 1916- Viti

Levu/ Fiji Islands

Wake-Eniwetok Wake-Eniwetok-

Marshall Isl.

WGS 72 World Geodetic System

1972

WGS 84 World Geodetic System

1984

Zanderij Zanderij- Surinam

A

Activating and Inverting Routes . .32

Active Route Page . . . . . . . . . . . .32

Alarms Setup . . . . . . . . . . . . . . . .53

Almanac Data . . . . . . . . . . . . . . . .2

Altitude Display . . . . . . . . . . . . . .18

Anchor Drag Alarm . . . . . . . . . . .53

Arrival Alarm . . . . . . . . . . . . . . . .53

B

Backlighting . . . . . . . . . . . . . . . .18

Bearing . . . . . . . . . . . . . . . . . . . . .2

C

CDI Alarm . . . . . . . . . . . . . . . . . .53

CDI Scale Settings . . . . . . . . . . . .49

Cancelling a GOTO . . . . . . . . . . .15

Caution . . . . . . . . . . . . . . . . . . . .iv

Clearing a Cluttered Map Display .15

Compass Page . . . . . . . . . . . . . . .37

Copying and Clearing Routes . . . .31

Course Made Good (CMG) . . . . . .2

Creating and Navigating Routes . .29

Crosstrack Error (XTE) . . . . . . . . .2

D

DGPS Interface . . . . . . . . . . . . . .44

Date and Time Setup . . . . . . . . . .46

Desired Track (DTK) . . . . . . . . . . .2

Differential GPS (DGPS) . . . . . . . . .2

Distance and Sun Calculation . . . .41

E

EZinit Option . . . . . . . . . . . . . . .17

Editing Existing Waypoints . . . . .24

Editing Routes . . . . . . . . . . . . . . .33

Estimated Time Enroute (ETE) . . . .2

Estimated Time of Arrival (ETA) . . .2

G

GPS Antenna . . . . . . . . . . . . . . . .55

Getting Started Tour . . . . . . . . . . .10

Glossary . . . . . . . . . . . . . . . . . . . .2

Going To a Waypoint (GOTO) . . .13

Grid . . . . . . . . . . . . . . . . . . . . . . .3

Ground Speed . . . . . . . . . . . . . . .3

APPENDIX E

Index

H

Highway Page . . . . . . . . . . . . . . .36

I

Index . . . . . . . . . . . . . . . . . . . . .65

Initialization Troubleshooting . . . . .7

Initializing . . . . . . . . . . . . . . . . . . .5

Installation . . . . . . . . . . . . . . . . .56

Interface Setup . . . . . . . . . . . . . . .43

L

Latitude . . . . . . . . . . . . . . . . . . . .3

Longitude . . . . . . . . . . . . . . . . . . .3

M

Magnetic Heading Reference . . . . .50

Man Overboard Function . . . . . . .26

Managing/Clearing the Track Log .42

Map Datums . . . . . . . . . . . . .48, 62

Map Page . . . . . . . . . . . . . . . . .9, 38

Map Setup and Orientation . . . . .51

Marking a Waypoint . . . . . . . . . .10

Mark & GOTO Wpts W/Cursor . .40
Marking and Saving Waypoints . .19

Menu Page . . . . . . . . . . . . . . . .9, 41

Message Page . . . . . . . . . . . . . . . .41

Messages & Time Offsets . . . . . . .60

Mounting the GPS 120XL . . . . . .56

N

Navigation . . . . . . . . . . . . . . . . . . .3

Navigation Basics . . . . . . . . . . . . . .4

Navigation Page . . . . . . . . . . . . . . .9

Navigation Setup . . . . . . . . . . . . .48

Navigation Simulator . . . . . . .10, 54

Nearest Waypoints Page . . . . . . . .20

65

APPENDIX E

Track Log Setup Page . . . . . . . . . .42

Trip Odometer . . . . . . . . . . . . . . .18

Index

O

On-Route GOTOs . . . . . . . . . . . .34

Overview . . . . . . . . . . . . . . . . . . .iii

P

Packing List . . . . . . . . . . . . . . . . .iii

Position . . . . . . . . . . . . . . . . . . . . .3

Position Formats . . . . . . . . . . . . .48

Position Page . . . . . . . . . . . . . .8, 18

Power/Data Cable . . . . . . . . . . . .58

Primary Pages . . . . . . . . . . . . . . . .8

R

Receiver Status and EPE . . . . . . . .17

Reference Waypoints . . . . . . . . . .23

Renaming and Deleting Waypoints 24

Route Definition Page . . . . . . . . . .30

S

Satellite Page . . . . . . . . . . . . . .8, 16

Scanning Waypoints . . . . . . . . . . .25

Screen Backlighting . . . . . . . . . . .18

Screen Contrast . . . . . . . . . . . . . .47

Selecting a GOTO Destination . . .26

Signal Strength Bars . . . . . . . . . . .16

Sky View . . . . . . . . . . . . . . . . . . .16

Speed Filter . . . . . . . . . . . . . . . . .49

System Setup . . . . . . . . . . . . . . . .46

U

Units of Measure . . . . . . . . . . . . .49

User-Defined Navigation Pages . . .34

Using the Compass Page . . . . . . .37

Using the Highway Page . . . . . . . .36

Using the Position and Map Pages 11

UTM Coordinates . . . . . . . . . . . . .3

V

Velocity Made Good (VMG) . . . . . .3

W

Warranty . . . . . . . . . . . . . . . . . . .67

Waypoint . . . . . . . . . . . . . . . . . . .3

Waypoint Comments . . . . . . . . . .24

Waypoint Definition Page . . . . . . .22

Waypoint List Page . . . . . . . . . . .21

Waypoint Submenus . . . . . . . . . .20

Wiring & Specifications . . . . . . . .58

Z

Zooming, Panning, and Pointing .39

T

Table of Contents . . . . . . . . . . . . . .1

Time Format . . . . . . . . . . . . . . . .47

Tone Setting . . . . . . . . . . . . . . . .47

TracBack . . . . . . . . . . . . . . . .27, 43

TracBack Tips . . . . . . . . . . . . . . .28

Track (TRK) . . . . . . . . . . . . . . . . . .3

Track Criteria . . . . . . . . . . . . . . . .42

Track Log Display . . . . . . . . . . . .52

66

LIMITED WARRANTY

GARMIN Corporation warrants this product to be free from
defects in materials and workmanship for one year from the date of
purchase. GARMIN will at its sole option, repair or replace any com­ponents which fail in normal use. Such repairs or replacement will
be made at no charge to the customer for parts or labor. The cus­tomer is, however, responsible for any transportation costs. This war­ranty does not cover failures due to abuse, misuse, accident or unau­thorized alteration or repairs. GARMIN assumes no responsibility for
special, incidental, punitive or consequential damages, or loss of use.

The warranties and remedies contained herein are exclusive and
in lieu of all other warranties expressed or implied, including any lia­bility arising under warranty of merchantability or fitness for a par­ticular purpose, statutory or otherwise. This warranty gives you spe­cific legal rights, which may vary from state to state.

To obtain warranty service, call the GARMIN Customer Service
department (913-397-8200) for a returned merchandise tracking
number. The unit should be securely packaged with the tracking
number clearly marked on the outside of the package, and sent
freight prepaid and insured to a GARMIN warranty service station. A
copy of the original sales receipt is required as the proof of purchase
for warranty repairs. GARMIN retains the exclusive right to repair or
replace the unit or software at its sole discretion.

®

© 1997 GARMIN Corporation

1200 E. 151st Street, Olathe, KS USA 66062

GARMIN (Europe) Ltd. - Unit 5, The Quadrangle,

Abbey Park, Romsey, UK SO51 9AQ

Part Number 190-00136-00 Rev. B Printed in Taiwan