Lowrance electronic M68C User Manual
www.lowrance.com
Pub. 988-0152-031
M68C S/Map &
M68C IceMachine
Fish-finding Sonar & Mapping GPS
Installation and Operation
Instructions
Copyright © 2003 Lowrance Electronics, Inc.
All rights reserved.
Lowrance
®
is a registered trademark of Lowrance Electronics, Inc.
Marine-Tex is a trademark of Illinois Tool Works Inc.
Lowrance Electronics may find it necessary to change or end our
policies, regulations, and special offers at any time. We reserve the
right to do so without notice. All features and specifications subject to
change without notice. All screens in this manual are simulated.
For free owner's manuals and other information,
visit our web site:
www.lowrance.com
Lowrance Electronics Inc.
12000 E. Skelly Dr.
Tulsa, OK USA 74128-2486
Printed in USA.
Table of Contents
Sec. 1: Read Me First! ..............................................................1
Capabilities and Specifications: M68............................................ 3
How your Sonar Works................................................................. 4
How your GPS Works ................................................................... 5
Introduction to GPS and WAAS................................................... 5
How to Use this Manual: Typographical Conventions................ 7
Sec. 2: Installation & Accessories .......................................... 9
Preparations.................................................................................. 9
Transducer Installation................................................................ 9
Recommended Tools and Supplies ......................................... 10
Selecting a Transducer Location................................................ 10
How Low Should You Go?....................................................... 11
Shoot-Thru-Hull vs. Transom Mounting ............................... 12
Transom Transducer Assembly and Mounting ......................... 13
Trolling Motor Bracket Installation........................................... 16
Transducer Orientation and Fish Arches.................................. 17
Shoot-Thru-Hull Preparation and Installation ......................... 18
Power and Cable Connections.................................................... 22
Mounting the Sonar Unit: In-Dash or Bracket ......................... 23
Portable Sonar Installation........................................................ 27
Portable Transducer Assembly .............................................. 29
Sec. 3: Basic Sonar Operation.............................................. 31
Keyboard Basics.......................................................................... 31
Memory........................................................................................ 32
Menus .......................................................................................... 32
Main Menu .............................................................................. 32
Sonar Menu ............................................................................. 33
Pages ........................................................................................... 35
Basic Sonar Quick Reference ............................................... 37
Sonar Operations ........................................................................ 38
Fish Symbols vs. Full Sonar Chart ........................................ 40
Other Free Training Aids ....................................................... 41
Sec. 4: Sonar Options & Other Features ...........................43
ASP (Advanced Signal Processing) ......................................... 43
Alarms ......................................................................................... 44
Depth Alarms .......................................................................... 44
Zone Alarm .............................................................................. 45
Fish Alarm............................................................................... 46
Chart Speed................................................................................. 47
ColorLine.................................................................................. 47
Depth Cursor............................................................................... 49
Depth Range - Automatic ........................................................... 49
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Depth Range - Manual................................................................ 50
Turn Auto Depth Range on Again:..................................... 50
Depth Range - Upper and Lower Limits ................................... 50
FasTrack .................................................................................. 52
Fish I.D. (Fish Symbols & Depths) ......................................... 52
FishTrack ................................................................................. 53
Overlay Data ............................................................................... 54
Change Displayed Data Font Size: ........................................ 55
Ping Speed & HyperScroll....................................................... 56
Reset Options .............................................................................. 57
Sensitivity & Auto Sensitivity.................................................... 58
Turn Auto Sensitivity Back on:.............................................. 59
Set Keel Offset ............................................................................59
Sonar Color Mode........................................................................ 60
Sonar Page & Sonar Chart Display Options ............................. 61
Full Sonar Chart ..................................................................... 61
Split Zoom Sonar Chart.......................................................... 61
Digital Data/Chart .................................................................. 62
Flasher..................................................................................... 62
Sonar Simulator.......................................................................... 63
Stop Chart ................................................................................... 63
Surface Clarity............................................................................ 64
Zoom Pan..................................................................................... 65
Sec. 5: Ice Fishing.................................................................... 67
Icemachine Mode Operation....................................................... 68
Sensitivity ............................................................................... 70
Colorline
Battery Gauge ......................................................................... 72
Sonar Signal Interpretation ....................................................... 72
Ice Flasher Options..................................................................... 73
Split Zoom Display Mode........................................................ 73
Color Modes............................................................................. 74
Scouting Through the Ice ...........................................................75
Sec. 6: Sonar Troubleshooting.............................................. 77
Sec. 7: Basic GPS Operations................................................ 81
Keyboard ..................................................................................... 81
Power/Lights (Turn Unit On and Off) ....................................... 82
Main Menu .................................................................................. 82
Pages ........................................................................................... 84
Sonar Page .............................................................................. 84
Satellite Status Page .............................................................. 84
Navigation Page...................................................................... 86
Full Map Page ......................................................................... 88
.............................................................................. 71
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GPS Quick Reference ............................................................. 91
Find your Current Position ........................................................ 92
Moving around the Map: Zoom & Cursor Arrow Keys.............. 92
Selecting any Map Item with the Cursor .................................. 93
Set a Waypoint............................................................................ 93
Create Waypoint at Current Position .................................... 93
Create Waypoint on Map........................................................ 94
Create Waypoint by Entering a Position ............................... 95
Navigate to a Waypoint .............................................................. 95
Set Man Overboard (MOB) Waypoint........................................ 96
Navigate Back to MOB Waypoint .............................................. 96
Navigate to Cursor Position on Map.......................................... 97
Navigate to a Map Place............................................................. 99
Creating and Saving a Trail....................................................... 99
Displaying a Saved Trail .......................................................... 101
Navigating Trails...................................................................... 101
Visual Trailing ...................................................................... 102
Navigate a Trail (Forward)................................................... 102
Navigate a Back Trail (Backtrack, or Reverse) ................... 104
Cancel Navigation..................................................................... 105
Sec. 8: Advanced GPS Operations .....................................107
Find Distance from Current Position to Another Location .... 107
Find Distance from Point to Point ........................................... 107
Icons........................................................................................... 107
Create Icon on Map............................................................... 108
Create Icon at Current Position ........................................... 108
Delete an Icon ....................................................................... 108
Navigate to an Icon............................................................... 109
Routes........................................................................................ 109
Create and Save a Route ......................................................110
Delete a Route ....................................................................... 112
Edit a Route .......................................................................... 112
Navigate a Route................................................................... 113
Navigate a Route in Reverse ................................................ 114
Trails ......................................................................................... 115
Delete a Trail ........................................................................ 115
Edit a Trail Name ................................................................. 115
Edit a Trail Color .................................................................. 116
Edit a Trail Pattern .............................................................. 116
Utilities...................................................................................... 116
Alarm Clock........................................................................... 116
Sun/Moon Rise & Set Calculator.......................................... 116
Trip Calculator...................................................................... 116
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Trip Down Timer................................................................... 116
Trip Up Timer ....................................................................... 117
Waypoints.................................................................................. 117
Delete a Waypoint................................................................. 117
Edit a Waypoint (Name, Symbol and Position) ................... 117
Selecting a Waypoint ............................................................ 118
Set a Waypoint by Average Position .................................... 118
Set a Waypoint by Projecting a Position.............................. 118
Sec. 9: System & GPS Setup Options................................. 119
Alarms ....................................................................................... 119
Auto Satellite Search................................................................ 120
Coordinate System Selection.................................................... 121
Map Fix ..................................................................................... 122
Customize Page Displays ......................................................... 124
Customize Map or Navigation Page..................................... 124
Customize Position Page ...................................................... 124
GPS Simulator .......................................................................... 125
Simulating Trail or Route Navigation ................................. 126
Initialize GPS............................................................................ 126
Map Auto Zoom......................................................................... 127
Map Data................................................................................... 127
Earth Map Detail .................................................................. 127
Pop-Up Map Info ................................................................... 128
Fill Water with White........................................................... 128
Map Overlays (Range Rings; Lat/Long Grid) ...................... 128
Map Datum Selection ............................................................... 128
Map Detail Category Selection................................................. 129
Map Orientation ....................................................................... 130
Overlay Data ............................................................................. 131
Pop-Up Help.............................................................................. 133
Reset Options ............................................................................ 134
Screen Contrast and Brightness .............................................. 134
Set Language ............................................................................ 135
Set Local Time .......................................................................... 135
Show WAAS Alarm................................................................... 136
Software Version Information.................................................. 136
Sounds and Alarm Sound Styles.............................................. 137
Track Smoothing....................................................................... 138
Trail Options ............................................................................. 138
Delete All Trails .................................................................... 139
Update Active Trail Option .................................................. 139
Update Trail Criteria (Auto, Time, Distance).................. 139
Trail Update Rate (Time, Distance)................................. 139
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Delete Trail ........................................................................... 140
New Trail............................................................................... 140
Trail Visible/Invisible and Other Trail Options .................. 141
Transparency ............................................................................ 141
Units of Measure....................................................................... 142
Sec. 10: Searching................................................................. 143
Find any Item Selected by Map Cursor ................................... 143
Find Map Places........................................................................ 144
Find Streets or Intersections.................................................... 146
Find Waypoints......................................................................... 150
Sec. 11: Supplemental Material.......................................... 153
Index......................................................................................... 159
A CAREFUL NAVIGATOR NEVER RELIES ON ONLY ONE METHOD
TO OBTAIN POSITION INFORMATION.
When showing navigation data to a position (waypoint), a GPS unit will show
the shortest, most direct path to the waypoint. It provides navigation data to the
waypoint regardless of obstructions. Therefore, the prudent navigator will not
only take advantage of all available navigation tools when traveling to a waypoint, but will also visually check to make sure a clear, safe path to the waypoint
is always available.
When a GPS unit is used in a vehicle, the vehicle operator is solely responsible for operating the vehicle in a safe manner. Vehicle operators
must maintain full surveillance of all pertinent driving, boating or flying conditions at all times. An accident or collision resulting in damage
to property, personal injury or death could occur if the operator of a
GPS-equipped vehicle fails to pay full attention to travel conditions and
vehicle operation while the vehicle is in motion.
WARNING!
CAUTION
WARNING!
v
Notes
vi
Section 1:
Read Me First!
How this manual can get you out on the water, fast!
Welcome to the exciting world of digital sonar and GPS! We know
you're anxious to begin finding fish, but we have a favor to ask. Before
you grab the unit and begin installing it, please give us a moment or
two to explain how our manual can help you get the best performance
from your combination fish finder and GPS receiver.
First, we want to thank you for buying a Lowrance sonar/GPS unit.
Whether you're a first time user or a professional fisherman, you'll discover that your unit is easy to use, yet capable of handling demanding
navigation and sonar tasks.
Our goal for this book is to get you on the water fast, with a minimum
of fuss. Like you, we'd rather spend more time boating or fishing and
less time reading the manual!
So, we designed our book so that you don't have to read the whole thing
from front to back for the information you want. At the start (or end) of
each segment, we'll tell you what content is coming up next. If it's a
concept you're already familiar with, we'll show you how and where to
skip ahead for the next important topic. We've also made it easy to look
up any tips you may need from time to time. Here's how:
The manual is organized into 11 sections. This first section is an introduction to the M68 sonar and GPS. It tells you the basics you need to
know before you can make the unit look around and tell you where you
are, or look below the surface to find some fish.
Section 2 will help you install your unit, as well as the transducer (the
most important part of any sonar installation). We'll also tell you about
some of the available accessories.
Section 3 covers Basic Sonar Operation. It will show you how easy it is
to run your sonar, right out of the box. This section features a one-page
Sonar Quick Reference. (If you've already jumped ahead and fig-
ured out how to install the unit yourself, and you just can't wait
any longer, turn to the Quick Reference on page 37 and head
for the water with your unit!)
After you've gained some experience with your sonar, you'll want to
check out Section 4, which discusses more advanced Sonar Options and
Other Features.
When you come to a sonar menu command on the unit's screen, you can
look it up in the manual by skimming over the table of contents or the in-
1
dex, or just flipping through Section 3 or scanning through the sonar options in Section 4.
Section 5 is a brief introduction to the powerful ice fishing applications of
the M68C and M68C IceMachine. (See section 2 to learn how you can get
the most out of your M68C with the addition of a special portable power
pack for ice fishing.)
If you're having difficulty with your sonar, you can find an answer to
the most common problems in Section 6, Sonar Troubleshooting.
The manual switches from sonar to navigation in Section 7, which introduces you to Basic GPS Operations. This section features a one-
page GPS Quick Reference on page 91.
Section 7 contains short, easy-to-scan GPS lessons that follow one another in chronological order. They're all you'll need to know to find your
way on the water quickly.
After you've learned the basics (or if you already have some GPS experience), you may want to try out some of the unit's many advanced
navigation features. That brings us to Section 8, Advanced GPS Opera-
tions. This section contains the rest of the unit's GPS command functions, organized in alphabetical order.
When you come to a GPS menu command on the screen, you can look it up
in the manual by skimming over the table of contents or index, just flipping
through Section 7 or scanning through the command portion of Section 8.
This unit is ready to use right out of the box, but you can fine tune and
customize its operation with dozens of options. Since sonar is the unit's
key feature, we put the main sonar options in Section 4. Some options,
such as screen brightness settings, affect both sonar and GPS operations. We describe how to use those common options along with GPS
options in Section 9, System Setup and GPS Setup Options. Section 9 is
organized in alphabetical order.
In Section 10, we go into more detail on one of the unit's most remarkable
GPS capabilities — Searching. There are so many map items you can
search for, we had to give this function its own section in the manual!
Finally, in Section 11, we offer Supplemental Material, including a list
of the GPS datums used, warranties and customer service information.
Now, if you're into the fine details, glance over the next segment on
specifications to see just how much sonar and GPS power your unit contains. It's important to us (and our power users), but, if you don't care
how many watts of power the unit has, or how many waypoints it can
store, skip ahead to important information on how sonar works, on page
4. (Background on GPS begins on page 5.)
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Capabilities and Specifications: M68
General
Display:............................ High-contrast Film SuperTwist LCD. Diago-
nal viewing area: 3.5" (8.9 cm).
Resolution:...................... 160 pixel x 240 pixel resolution; 38,400 total
pixels.
Backlighting:.................. LED backlit screen with multiple lighting lev-
els; backlit keypad.
Input power:................... 10 to 17 volts DC.
Current drain: ............... 170 ma lights off; 240 ma lights on.
Case size:......................... 5.8" H x 4.3" W x 2.5" D (14.7 cm H x 10.8 cm
W x 6.6 cm D) sealed, waterproof; suitable for
saltwater use.
Back-up memory: .......... Built-in memory stores GPS data for dec-
ades. User settings are stored when unit is
turned off.
Languages:...................... 10; menu languages selectable by user.
Sonar
Frequency:...................... 200 kHz.
Transducer:...................... A Skimmer
your sonar unit. Its 20° cone angle offers a
wide fish detection area of up to 60º with
high sensitivity settings. Operates at boat
speeds up to 70 mph (61 kts).
Transmitter: ................... 800 watts peak-to-peak; 100 watts RMS.
Sonar sounding
depth capability: ........... 600 feet (180 meters). Actual capability de-
pends on transducer configuration and installation, bottom composition and water conditions. All sonar units typically read deeper
in fresh water than in salt water.
Depth display:................ Continuous display.
Audible alarms: ............. Deep/shallow/fish/zone.
Automatic ranging:....... Yes, with instant screen updates.
Auto bottom track:........ Yes
Zoom bottom track: ...... Yes.
Split-screen zoom:......... Yes.
Surface water temp: ..... Yes, built into transducer.
transducer comes packed with
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GPS
Receiver/antenna: ......... Internal 12 parallel channel GPS/WAAS.
Position updates: .......... Every second.
Position points: ............. 1,000 waypoints; 1,000 event marker icons.
Man Overboard:............. MOB feature precisely marks man overboard
location with special icon, then automatically
displays navigation data to that position.
Audible alarms: ............. Arrival/off-course/destination passed/anchor.
Graphic symbols for
waypoints or event
marker icons: ................. 42.
Routes:............................. 100; up to 100 waypoints per route.
Plot Trails: ...................... 10 savable; up to 9,999 points per trail.
Zoom range:.................... 39 ranges; 0.02 to 4,000 miles.
NOTICE!
The storage and operation temperature range for your unit is from
-4 degrees to +167 degrees Fahrenheit (-20 degrees to +75 degrees
Celsius). Extended storage or operation in temperatures higher or
lower than specified will damage the liquid crystal display in your
unit. This type of damage is not covered by the warranty. For more
information, contact the factory's Customer Service Department;
phone numbers are listed on the last page.
How Your Sonar Works
Sonar has been around since the 1940s, so if you already know how it
works, skip down to read about the relatively new technology of GPS.
But, if you've never owned a sonar fish finder, this segment will tell you
the underwater basics.
Sonar is an abbreviation for SOund NA
ogy developed during World War II for tracking enemy submarines.
(Lowrance developed the world's first transistorized sportfishing sonar in
1957.) A sonar consists of a transmitter, transducer, receiver and display. In simple terms, here's how it finds the bottom, or the fish:
The transmitter emits an electrical impulse, which the transducer converts into a sound wave and sends into the water. (The sound frequency
can't be heard by humans or fish.) The sound wave strikes an object
(fish, structure, bottom) and bounces back to the transducer, which
converts the sound back into an electrical signal.
The receiver amplifies this return signal, or echo, and sends it to the
vigation and Ranging, a technol-
4
display, where an image of the object appears on the scrolling sonar
chart. The sonar's microprocessor calculates the time lapse between the
transmitted signal and echo return to determine the distance to the
object. The whole process repeats itself several times each second.
How Your GPS Works
You'll navigate faster and easier if you understand how this unit scans
the sky to tell you where you are on the earth — and, where you're going. (But if you already have a working understanding of GPS receivers
and the GPS navigation system, skip on ahead to Section 2, Installation
& Accessories on page 9. If you're new to GPS, read on, and you can later
impress your friends with your new-found knowledge.)
First, think of your unit as a small but powerful computer. (But don't
worry — we made this unit easy to use, so you don't need to be a computer
expert to find your way!) The unit includes a keypad and a screen with
menus so you can tell it what to do. The screen also lets the unit show your
location on a moving map, as well as point the way to your destination.
This unit uses an internal antenna/receiver module, which makes the
whole system work something like your car radio. But instead of your
favorite dance tunes, this receiver tunes in to a couple of dozen GPS
satellites circling the earth. (It will also listen in to the WAAS satellites
in orbit, but more about that in the upcoming segment introducing you
to GPS and WAAS.)
Your unit listens to signals from as many satellites as it can "see" above
the horizon, eliminates the weakest signals, then computes its location
in relation to those satellites. Once it figures its latitude and longitude,
the unit plots that position on the GPS screen. The whole process takes
place several times a second!
Another portion of the unit's onboard memory is devoted to recording GPS
navigation information, which includes waypoints, event marker icons,
trails and routes. This lets you look back the way you came, and retrace
your path. Think of this data storage like the hard drive memory in a
computer or a tape in a cassette tape recorder. You can save several different GPS data files, erase 'em and record new ones, over and over again.
Introduction to GPS and WAAS
Well, now you know the basics of how the unit does its work. You might
be ready to jump ahead to Section 2, Installation & Accessories, on page
13, so you can mount your unit and plug in the power. Or you might
want to see how our text formatting makes the manual tutorials easy to
skim. If that's the case, move on to "How to Use This Manual" on page
10. But, if you want to understand the current state of satellite navigation, look over this segment describing how GPS and its new companion
5
WAAS work together to get you where you're going.
The Global Positioning System (GPS) was launched July 17, 1995 by
the United States Department of Defense. It was designed as a 24hour-a-day, 365-days-a-year, all weather global navigation system for
the armed forces of the U.S. and its allies. Civilian use was also available at first, but it was less accurate because the military scrambled
the signal somewhat, using a process called Selective Availability (SA.)
GPS proved so useful for civilian navigation that the federal government discontinued SA on May 2, 2000, after the military developed
other methods to deny GPS service to enemy forces. Reliable accuracy
for civilian users jumped from 100 meters (330 feet) under SA to the
present level of 10 to 20 meters (about 30 to 60 feet.)
Twenty-four satellites orbit 10,900 nautical miles above the Earth,
passing overhead twice daily. A series of ground stations (with precisely
surveyed locations) controls the satellites and monitors their exact locations in the sky. Each satellite broadcasts a low-power signal that identifies the satellite and its position above the earth. Three of these satellites
are spares, unused until needed. The rest virtually guarantee that at
least four satellites are in view nearly anywhere on Earth at all times.
The system requires signal reception from three satellites in order to
determine a position. This is called a 2D fix. It takes four satellites to
determine both position and elevation (your height above sea level —
also called altitude). This is called a 3D fix.
A minimum of three satellites are required to determine a 2D fix.
Remember, the unit must have a clear view of the satellites in order to
receive their signals. Unlike radio or television signals, GPS works at
very high frequencies. These signals can be easily blocked by trees,
buildings, an automobile roof, even your body.
6
Like most GPS receivers, this unit doesn’t have a compass or any other
navigation aid built inside. It relies solely on the signals from the satellites to calculate a position. Speed, direction of travel, and distance
are all calculated from position information. Therefore, in order for the
unit to determine direction of travel, you must be moving and the
faster, the better. This is not to say that it won’t work at walking or
trolling speeds — it will. There will simply be more "wandering" of the
data shown on the display.
GPS alone is plenty accurate for route navigation, but the U.S. Federal
Aviation Administration has special aircraft navigation needs that go
beyond basic GPS. So, the FAA has developed a program to boost GPS
performance with its Wide Area Augmentation System, or WAAS. The
FAA commissioned the system on July 11, 2003.
WAAS is designed to increase GPS accuracy to within 7.6 meters vertically
and horizontally, but it consistently delivers accuracies within 1-2 meters
horizontal and 2-3 meters vertical, according to the FAA. It does this by
broadcasting correction signals on GPS frequencies. Your unit automatically receives both GPS and WAAS signals.
However, there are some fringe areas of the U.S., including parts of
Alaska, that do not yet receive robust WAAS coverage. Continued WAAS
development is planned to extend WAAS coverage in the years to come.
WAAS boosts the accuracy of land GPS navigation, but the system is
designed for aircraft. The satellites are in a fixed orbit around the
Equator, so they appear very low in the sky to someone on the ground
in North America. Aircraft and vessels on open water can get consistently good WAAS reception, but terrain, foliage or even large man-made
structures can sometimes block the WAAS signal from ground receivers.
You'll find that using your GPS receiver is both easy and amazingly
accurate. It’s easily the most accurate method of electronic navigation
available to the general public today. Remember, however, that this
receiver is only a tool. Always have another method of navigation available, such as a map or chart and a compass.
Also remember that this unit will always show navigation information
in the shortest line from your present position to a waypoint, regardless
of terrain! It only calculates position, it can’t know what’s between you
and your destination, for example. It’s up to you to safely navigate
around obstacles, no matter how you’re using this product.
How to use this manual: typographical conventions
Many instructions are listed as numbered steps. The keypad and arrow
"keystrokes" appear as boldface type. So, if you're in a real hurry (or
just need a reminder), you can skim the instructions and pick out what
7
menu command to use by finding the boldface command text. The following paragraphs explain how to interpret the text formatting for
those commands and other instructions:
Arrow Keys
The arrow keys control the movement of dotted cross-hair lines on your
mapping screen called the cursor. The arrow keys also control a horizontal line depth cursor on the sonar screen. The arrow keys help you
move around the menus so you can execute different commands. They
are represented by symbols like these, which denote the down arrow
key, the up arrow, the left arrow and the right arrow: ↓ ↑ ← →.
Keyboard
The other keys perform a variety of functions. When the text refers to a
key to press, the key is shown in bold, sans serif type. For example, the
"Enter/Icons" key is shown as
ENT and the "Menu" key is shown as MENU.
Menu Commands
A menu command or a menu option will appear in small capital letters, in
a bold sans serif type like this:
ROUTE PLANNING. These indicate that you are
to select this command or option from a menu or take an action of some
kind with the menu item. Text that you may need to enter or file names
you need to select are show in italic type, such as trail name.
Instructions = Menu Sequences
Most functions you perform with this unit are described as a sequence
of key strokes and selecting menu commands. We've written them in a
condensed manner for quick and easy reading.
For example, instructions for navigating a trail would look like this:
1. From the Plotter Page, press
2. Press ↓ to Trail 1|
ENT|→|↓ to NAVIGATE|ENT.
MENU|MENU|↓ to MY TRAILS|ENT.
3. You are asked to wait while it converts the trail into a route.
4. The wait message disappears and the unit begins showing navigation information along the trail. Now, begin moving and follow
your unit's directions.
Translated into complete English, step 1 above would mean: "Start on
the Plotter Page. Press the Menu key twice. Next, repeatedly press (or
press and hold) the down arrow key to scroll down the menu and select
(highlight) the My Trails menu command. Finally, press the Enter key."
Step 2 would mean: "Press the down arrow key repeatedly to scroll to
the trail named Trail 1, and press Enter. Next, press the right arrow
key and then the down arrow key to highlight the Navigate command,
then press Enter."
8
Section 2:
Installation & Accessories
Preparations
You can install the sonar and GPS systems in some other order if you
prefer, but we recommend this installation sequence:
CAUTION:
You should read over this entire installation section before drilling any holes in your vehicle or vessel!
1. Determine the approximate location for the sonar/GPS unit, so you
can plan how and where to route the power/transducer cable. This will
help you make sure you have enough cable length for the desired configuration.
2. Determine the approximate location for the transducer and its cable
route.
3. Determine the location of your battery or other power connection,
along with the power cable route.
4. Install the transducer and route the transducer cable to the sonar/GPS unit.
5. Route the power cable from the unit's location to an appropriate
power source and connect it there.
6. Connect the transducer/power cable to the unit and mount the sonar/GPS unit to the bracket.
Transducer Installation
These instructions will help you install your Skimmer
transom, on a trolling motor or inside a hull. Please read all instructions before proceeding with any installation.
Your Skimmer transducer typically comes packaged with a one-piece
stainless steel bracket for mounting it to the transom of your boat. The
optional trolling motor mount uses a one-piece plastic bracket with an
adjustable strap. These are "kick-up" mounting brackets. They help prevent damage if the transducer strikes an object while the boat is moving.
If the transducer does "kick-up," the bracket can easily be pushed back
into place without tools.
Read these instructions carefully before attempting the installation.
Determine which of the installation methods is right for your boat.
9
transducer on a
Remember, the transducer location and installation is the most
critical part of a sonar installation.
Recommended Tools and supplies
If you prefer the option of routing the cable through the transom, you
will need a 5/8" drill bit.
NOTE:
The following installation types also call for these recommended
tools and required supplies that you must provide (supplies listed
here are not included):
Transom installation
Tools include: two adjustable wrenches, drill, #29 (0.136") drill bit, flathead screwdriver. Supplies: high quality, marine grade above- or below-
waterline sealant/adhesive compound.
Trolling motor installations
Tools: two adjustable wrenches, flat-head screwdriver. Supplies: plastic
cable ties.
Shoot-through hull installations
Tools: these will vary depending on your hull's composition. Consult your
boat dealer or manufacturer. Other tools are a wooden craft stick or
similar tool for stirring and applying epoxy, and a paper plate or piece
of cardboard to mix the epoxy on. Supplies: rubbing alcohol, 100 grit
sandpaper, specially formulated epoxy adhesive available from LEI (see
ordering information on the inside back cover). A sandwich hull also
requires polyester resin.
Selecting a Transducer Location
1. The location must be in the water at all times, at all operating speeds.
2. The transducer must be placed in a location that has a smooth flow of
water at all times. If the transducer is not placed in a smooth flow of
water, interference caused by bubbles and turbulence will show on
the sonar's display in the form of random lines or dots whenever the
boat is moving.
NOTE:
Some aluminum boats with strakes or ribs on the outside of the
hull create large amounts of turbulence at high speed. These boats
typically have large outboard motors capable of propelling the boat
at speeds faster than 35 mph. Typically, a good transom location on
aluminum boats is between the ribs closest to the engine.
3. The transducer should be installed with its face pointing straight
down, if possible. For shoot-thru applications: Many popular fishing
10
boat hulls have a flat keel pad that offers a good mounting surface. On
prevent the transducer from
location
Deadrise less than 10
vee hulls, try to place the transducer where the deadrise is 10° or less.
°
Pad
Left, vee pad hull; right, vee hull. A pod style transducer is shown
here, but the principle is the same for Skimmers inside a hull.
Strakes
4. If the transducer is mounted on the transom, make sure it doesn't
interfere with the trailer or hauling of the boat. Also, don't mount it
closer than approximately one foot from the engine's lower unit. This
will prevent cavitation (bubble) interference with propeller operation.
5. If possible, route the transducer cable away from other wiring on the
boat. Electrical noise from engine wiring, bilge pumps and aerators
can be displayed on the sonar's screen. Use caution when routing the
transducer cable around these wires.
CAUTION: Clamp the transducer cable to transom near
the transducer. This will help
entering the boat if it is
knocked off at high speed.
Good location
Poor location
Good
Poor angle
Good and poor transducer locations.
Good location
How low should you go?
For most situations, you should install your Skimmer transducer so
that its centerline is level with the bottom of the boat hull. This will
usually give you the best combination of smooth water flow and protection from bangs and bumps.
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Transom
Transducer
centerline
Hull bottom
Align transducer centerline with hull bottom.
However, there are times when you may need to adjust the transducer
slightly higher or lower. (The slots in the mounting brackets allow you
to loosen the screws and slide the transducer up or down.) If you frequently lose bottom signal lock while running at high speed, the transducer may be coming out of the water as you cross waves or wakes.
Move the transducer a little lower to help prevent this.
If you cruise or fish around lots of structure and cover, your transducer
may be frequently kicking up from object strikes. If you wish, you may
move the transducer a little higher for more protection.
There are two extremes you should avoid. Never let the edge of the
mounting bracket extend below the bottom of the hull. Never let the
bottom – the face – of the transducer rise above the bottom of the hull.
Shoot-thru-hull vs. Transom Mounting
In a shoot-thru-hull installation, the transducer is bonded to the inside
of the hull with epoxy. The sonar "ping" signal actually passes through
the hull and into the water. This differs from a bolt-thru-hull installation (often called simply "thru-hull"). In that case, a hole is cut in the
hull and a specially designed transducer is mounted through the hull
with a threaded shaft and nut. This puts the transducer in direct contact
with the water.
Typically, shoot-thru-hull installations give excellent high speed operation and good to excellent depth capability. There is no possibility of
transducer damage from floating objects, as there is with a transommounted transducer. A transducer mounted inside the hull can't be
knocked off when docking or loading on a trailer.
However, the shoot-thru-hull installation does have its drawbacks.
First, some loss of sensitivity does occur, even on the best hulls. This
varies from hull to hull, even from different installations on the same
hull. This is caused by differences in hull lay-up and construction.
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Second, the transducer angle cannot be adjusted for the best fish arches
on your sonar display. (This is not an issue for flasher-style sonars.)
Lack of angle adjustment can be particularly troublesome on hulls that
sit with the bow high when at rest or at slow trolling speeds.
Third, a transducer CAN NOT shoot through wood and metal hulls.
Those hulls require either a transom mount or a thru-hull installation.
Fourth, if your Skimmer transducer has a built in temp sensor, it will
only show the temperature of the bilge, not the water surface temp.
Follow the testing procedures listed in the shoot-thru-hull installation
section at the end of this lesson to determine if you can satisfactorily
shoot through the hull.
TRANSOM TRANSDUCER ASSEMBLY AND MOUNTING
The best way to install the transducer is to loosely assemble all of the
parts first, place the transducer's bracket against the transom and see if
you can move the transducer so that it's parallel with the ground.
1. Assembling the bracket. Press the two small plastic ratchets into the
sides of the metal bracket as shown in the following illustration. Notice
there are letters molded into each ratchet. Place each ratchet into the
bracket with the letter "A" aligned with the dot stamped into the metal
bracket. This position sets the transducer's coarse angle adjustment for a
14° transom. Most outboard and stern-drive transoms have a 14° angle.
Dot
Align plastic ratchets in bracket.
2. Aligning the transducer on the transom. Slide the transducer
between the two ratchets. Temporarily slide the bolt though the
transducer assembly and hold it against the transom. Looking at the
transducer from the side, check to see if it will adjust so that its face
is parallel to the ground. If it does, then the "A" position is correct for
your hull.
If the transducer's face isn't parallel with the ground, remove the
transducer and ratchets from the bracket. Place the ratchets into the
holes in the bracket with the letter "B" aligned with the dot stamped
in the bracket.
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Reassemble the transducer and bracket and place them against the
transom. Again, check to see if you can move the transducer so it's
parallel with the ground. If you can, then go to step 3. If it doesn't,
repeat step 2, but use a different alignment letter until you can place
the transducer on the transom correctly.
Ratchets
Insert bolt and check transducer position on transom.
3. Assembling the transducer. Once you determine the correct position for the ratchets, assemble the transducer as shown in the following figure. Don't tighten the lock nut at this time.
Metal
Nut
washer
Rubber
washers
Assemble transducer and bracket.
Metal washer
Bolt
4. Drilling mounting holes. Hold the transducer and bracket assembly
against the transom. The transducer should be roughly parallel to the
ground. The transducer's centerline should be in line with the bottom
of the hull. Don't let the bracket extend below the hull!
Mark the center of each slot for the mounting screw pilot holes. You
will drill one hole in the center of each slot.
Drill the holes using the #29 bit (for the #10 screws).
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Transom
Flat-bottom hull
Transom
Position transducer mount on transom and mark mounting holes.
Side view shown at left and seen from above at right.
5. Attaching transducer to transom. Remove the transducer from
the bracket and re-assemble it with the cable passing through the
bracket over the bolt as shown in the following figures.
Route cable over bolt and through bracket. Side view shown at left and
seen from above at right.
Attach the transducer to the transom. Slide the transducer up or
down until it's aligned properly with the bottom of the hull as shown
in the preceding and following figures. Tighten the bracket's mounting screws, sealing them with the sealant/adhesive compound.
Adjust the transducer so that it's parallel to the ground and tighten
the nut until it touches the outer washer, then add 1/4 turn. Don't
over tighten the lock nut! If you do, the transducer won't "kick-up" if
it strikes an object in the water.
Align transducer centerline with hull bottom and attach to transom.
Bottom
of
hull
Deep-"vee" hull
15
6. Route the transducer cable through or over the transom to
Flat washer
the sonar unit. Make sure to leave some slack in the cable at the
transducer. If possible, route the transducer cable away from other
wiring on the boat. Electrical noise from the engine's wiring, bilge
pumps, VHF radio wires and cables, and aerators can be picked up by
the sonar. Use caution when routing the transducer cable around
these wires.
WARNING:
Clamp the transducer cable to the transom close to the
transducer. This can prevent the transducer from entering the boat if it is knocked off at high speed.
If you need to drill a hole in the transom to pass the connector through,
the required hole size is 5/8".
Caution:
If you drill a hole in the transom for the cable, make sure it is located above the waterline. After installation, be sure to seal the
hole with the same marine grade above- or below-waterline sealant/adhesive used for the mounting screws.
7. Make a test run to determine the results. If the bottom is lost at
high speed, or if noise appears on the display, try sliding the transducer bracket down. This puts the transducer deeper into the water,
hopefully below the turbulence causing the noise. Don't allow the
transducer bracket to go below the bottom of the hull!
TROLLING MOTOR BRACKET INSTALLATION
1. Attach the optional TMB-S bracket to the transducer as shown in the
following figure, using the hardware supplied with the transducer.
(Note: The internal tooth washer is supplied with the TMB-S.)
Bolt
Attach motor mounting bracket to transducer.
Internal tooth washer
Nut
2. Slide the adjustable strap supplied with the TMB-S through the slot
in the transducer bracket and wrap it around the trolling motor. Position the transducer to aim straight down when the motor is in the
water. Tighten the strap securely.
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TMB-S bracket
3. Route the transducer cable alongside the trolling motor shaft. Use
plastic ties (not included) to attach the transducer cable to the trolling motor shaft. Make sure there is enough slack in the cable for the
motor to turn freely. Route the cable to the sonar unit and the transducer is ready for use.
Transducer mounted on trolling motor, side view.
TRANSDUCER ORIENTATION AND FISH ARCHES
If you do not get good fish arches on your display, it could be because
the transducer is not parallel with the ground when the boat is at rest
in the water or at slow trolling speeds.
Transducer aimed
too far back
Full fish arch
Transducer angles and their effects on fish arches.
Partial fish arches
Proper transducer angle
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Transducer aimed
too far forward
If the arch slopes up – but not back down – then the front of the transducer is too high and needs to be lowered. If only the back half of the
arch is printed, then the nose of the transducer is angled too far down
and needs to be raised.
NOTE:
Periodically wash the transducer's face with soap and water to remove any oil film. Oil and dirt on the face will reduce the sensitivity
or may even prevent operation.
SHOOT-THRU-HULL PREPARATION
Hulls With Floatation Materials
The transducer installation inside a fiberglass hull must be in an area
that does not have air bubbles in the resin or separated fiberglass layers. The sonar signal must pass through solid fiberglass. A successful
transducer installation can be made on hulls with flotation materials
(such as plywood, balsa wood or foam) between layers of fiberglass if
the material is removed from the chosen area. See the figure below.
WARNING:
Do not remove any material from your inner hull unless
you know the hull's composition. Careless grinding or
cutting on your hull can result in damage that could sink
your boat. Contact your boat dealer or manufacturer to
confirm your hull specifications.
Fill with polyester resin
Flotation material
Epoxy to hull first
Epoxy the transducer to a solid portion of the hull.
Inner hull
Outer hull
For example, some (but not all) manufacturers use a layer of fiberglass,
then a core of balsa wood, finishing with an outer layer of fiberglass.
Removing the inner layer of fiberglass and the balsa wood core exposes
the outer layer of fiberglass. The transducer can then be epoxied directly to the outer layer of fiberglass. After the epoxy cures for 24
hours, fill the remaining space with polyester resin. When the job is
finished, the hull is watertight and structurally sound. Remember, the
sonar signal must pass through solid fiberglass. Any air bubbles in the
fiberglass or the epoxy will reduce or eliminate the sonar signals.
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Testing Determines Best Location
Second bottom
True bottom
Ideally, the shoot-thru transducer should be installed as close to the
transom as possible, close to the centerline. This will give you the best
performance during high speed maneuvers.
Transducer location
(high speed)
Shoot-thru-hull transducer locations for
high speed or trolling speed operation.
Transducer location
(trolling speed)
To choose the proper location for shoot-thru-hull mounting, follow these
testing procedures: (You may need a helper to complete these steps.)
1. Anchor the boat in about 30 feet of water. Add a little water to the
sump of the boat. Plug the transducer into the sonar unit, turn it on,
then hold the transducer over the side of the boat in the water. Adjust
the sensitivity and range controls until a second bottom echo is seen on
the display. (You'll need to turn off Auto Sensitivity, Auto Depth Range
and ASP. Try a range setting that is two to three times the water
depth. The harder (more rocky) the bottom, the easier it will be to get a
second bottom signal.) Don't touch the controls once they've been set.
Example of a second bottom signal. Unit is in 30 feet of water, with
Manual range setting
range set at 80 feet and sensitivity set at 87 percent.
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2. Next, take the transducer out of the water and place it in the water in
the sump of the boat, face down. (The transducer face is shown in the
figure on the following page.) Notice how the signal strength decreases. The second bottom signal will probably disappear and the bottom signal intensity will likely decrease.
3. Now move the transducer around to find the best location with the
strongest possible bottom signal. If you find a spot with an acceptable
bottom signal, mark the location and move on to step 4.
If you can't get an acceptable bottom signal, try turning up the sensitivity by three or five keystrokes and then move the transducer around
once more. If you find a spot that works, mark it and move on to step 4.
If you have to turn up sensitivity by more than five keystrokes to get a
good signal, the transducer should be mounted on the outside of the
hull. This is especially true if you have to turn sensitivity all the way
up to get a decent bottom signal.
4. Most people can get good results by following steps 1 through 3, so this
step is optional. If you want to make an extra effort to be absolutely sure
that your selected location will work under all conditions, make a test
run with the boat on plane and observe the bottom signal. You'll need to
figure some way to prop the transducer into position while you make
your test run. (A brick or two might be sufficient to hold it in place.)
5. When you're satisfied with a location, mark it and proceed with
the installation.
Shoot-thru-hull Installation
If you are installing the transducer on a hull with floatation material
sandwiched within the hull, refer to the text "Hulls With Flotation Materials" beginning on page 18.
1. Make sure the area is clean, dry and free of oil or grease, then sand
both the inside surface of the hull and the face of the transducer with
100 grit sandpaper. The sanded hull area should be about 1-1/2 times
the diameter of the transducer. The surface of the hull must be flat
so the entire transducer face is in contact with the hull prior to
bonding. After sanding, clean the hull and transducer with rubbing
alcohol to remove any sanding debris.
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Spread epoxy here
Sand this surface
Epoxy transducer to hull.
WARNING:
Use only the epoxy available from LEI. It has been for-
mulated to work with these installation procedures.
Other epoxy types may be too thin or may not cure to the
right consistency for optimum transducer performance.
2. The epoxy consists of the epoxy itself and a hardener. Remove the
two compounds from the package and place them on the paper plate.
Thoroughly stir the two compounds together until the mixture has a
uniform color and consistency. Do not mix too fast or bubbles will
form in the epoxy. After mixing, you have 20 minutes to complete the
installation before the epoxy becomes unworkable.
Spread a thin layer of epoxy (about 1/16" or 1.5 mm thick) on the face
of the transducer as shown in the previous figure. Make sure there
are no air pockets in the epoxy layer! Then, apply the remaining epoxy to the sanded area on the hull.
3. Press the transducer into the epoxy, twisting and turning it to force
any air bubbles out from under the transducer face. Stop pressing
when you bottom out on the hull. When you're finished, the face of
the transducer should be parallel with the hull, with a minimum
amount of epoxy between the hull and transducer.
4. Apply a weight, such as a brick, to hold the transducer in place while
the epoxy cures. Be careful not to bump the transducer while the epoxy is wet. Leave the weight in place for a minimum of three hours.
Allow the epoxy to cure for 24 hours before moving the boat.
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5. After the epoxy has cured, route the cable to the sonar unit and it's
for saltw
a
ter installations
ready to use.
POWER AND CABLE CONNECTIONS
The unit works from a 12-volt battery system. For the best results, attach the power cable directly to the battery. You can attach the power
cable to an accessory or power buss, however you may have problems
with electrical interference. Therefore, it's safer to go ahead and attach
the power cable directly to the battery.
CAUTION:
When using the unit in a saltwater environment, we strongly recommend that you shut off the power supply to the power cable when
the unit is not in use. When the unit is turned off but still connected
to a power supply, electrolysis can occur in the power cable plug.
This may result in corrosion of the plug body along with the electrical contacts in the cable and the unit's power socket.
In saltwater environments we recommend you connect the power
cable to the auxiliary power switch included in most boat designs.
If that results in electrical interference, or if such a switch is not
available, we recommend connecting direct to the battery and installing an inline switch. This will let you shut off power to the
power cable when the unit is not in use. When you are not using
the unit, you should always shut off power to the power cable, especially when the power cable is disconnected from the unit.
To unit
Black wire
Power and transducer connections for the M68 sonar
units (direct battery connection shown).
Optional power off switch
12 volt
battery
Red wire with
3 amp fuse
If possible, keep the power cable away from other boat wiring, especially the engine's wires. This will provide the best isolation from electrical noise. If the cable is not long enough, splice #18 gauge wire onto
it. The power cable has two wires, red and black. Red is the positive
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