chartplotting receiver

GPSMAP 198C Sounder

owners manual
Copyright 2005 Garmin Ltd. or its subsidiaries Garmin International, Inc. 1200 East 151st Street, Olathe, Kansas 66062, U.S.A. Tel. 913/397.8200 or 800/800.1020 Fax 913/397.8282 Garmin (Europe) Ltd. Unit 5, The Quadrangle, Abbey Park Industrial Estate, Romsey, SO51 9DL, U.K. Tel. 44/0870.8501241 Fax 44/0870.8501251 Garmin Corporation No. 68, Jangshu 2nd Road, Shijr, Taipei County, Taiwan Tel. 886/2.2642.9199 Fax 886/2.2642.9099
All rights reserved. Except as expressly provided herein, no part of this manual may be reproduced, copied, transmitted, disseminated, downloaded or stored in any storage medium, for any purpose without the express prior written consent of Garmin. Garmin hereby grants permission to download a single copy of this manual onto a hard drive or other electronic storage medium to be viewed and to print one copy of this manual or of any revision hereto, provided that such electronic or printed copy of this manual must contain the complete text of this copyright notice and provided further that any unauthorized commercial distribution of this manual or any revision hereto is strictly prohibited. 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. Visit the Garmin Web site (www.garmin.com) for current updates and supplemental information concerning the use and operation of this and other Garmin products. Garmin, GPSMAP, AutoLocate, TracBack, BlueChart, and MapSource are registered trademarks of Garmin Ltd. or its subsidiaries and may not be used without the express permission of Garmin.

July 2005

Part Number 190-00541-00 Rev. B

Printed in Taiwan

INTRODUCTION > ABOUT THIS MANUAL

INTRODUCTION

Thank you for choosing the Garmin GPSMAP 198C Sounder. The GPSMAP 198C Sounder utilizes the proven performance of Garmin GPS and full-featured mapping to create an unsurpassed portable GPS receiver. Take a moment now to compare the contents of this package with the packing list on the outside of the box. If any pieces are missing, contact your Garmin dealer immediately. Before you begin working with the GPSMAP 198C Sounder, review the installation instructions listed in the Appendix. If you have any question about installing your chartplotter, contact Garmin Product Support or a professional installer. The GPSMAP 198C Sounder Quick Reference Guide contains helpful tips on using the unit and performing various navigation tasks. Its a good idea to keep the Quick Reference Guide nearby whenever you are operating your new GPSMAP 198C Sounder.

About This Manual

To get the most out of your new navigation system, take time to read this manual and learn the operating procedures for your unit in detail. This manual is organized into the following chapters. The Introduction section contains the Table of Contents as well as GPSMAP 198C Sounder care information. The Basic Operation section provides you with detailed information and step-by-step directions for features such as using the Find Menu, navigating a route, and using waypoints. The Main Pages section provides detailed explanations about each page in the GPSMAP 198C Sounder and step-by-step directions on using the pages. The Main Menu section provides detailed explanations about the Main Menu and how to use it to congure your unit. The Appendix contains installation instructions, specications, optional accessories, and maintenance information. You can also nd warranty and FCC information in the Appendix. Read the Safety Information to learn how to install and use your Garmin GPSMAP 198C Sounder safely and responsibly. An Index is provided at the end of the manual for reference.
GPSMAP 198C Sounder Owners Manual
INTRODUCTION > TABLE OF CONTENTS

BASIC OPERATION > SIMULATOR MODE

Simulator Mode

Simulator Mode turns the GPS receiver off for use indoors or practice. Any of the functions discussed in the following pages can be performed in Simulator Mode. While in Simulator Mode, a Running Simulator message appears after 2 minutes of inactivity. Keep in mind that the GPSMAP 198C Sounder does not track satellites in Simulator Mode, and this mode should never be used for actual navigation. All the waypoint and route planning completed in Simulator Mode is retained in memory for future use.
WARNING: Do not attempt to navigate using Simulator Mode. When the unit is set to Simulator Mode, the GPS receiver is turned off. Any satellite signal strength bars shown are only simulations and do not represent the strength of actual satellite signals.
1. Press MENU twice to show the Main Menu. Press up or down on the ROCKER until the GPS tab is highlighted, and then press MENU once. 2. Use the ROCKER to highlight Start Simulator, and press ENTER. Choose No to the retail demonstration, and press ENTER. 3. Press ENTER to conrm the Running Simulator message that appears at the bottom of the screen. Simulating appears at the top of each of the Main Pages. 4. To turn off the Simulator Mode, press MENU, and select Stop Simulator.
To place the GPSMAP 198C Sounder in Simulator Mode:
BASIC OPERATION > ADJUSTING THE BACKLIGHT
The Set Position, Track Control, Track and Speed elds only show while in Simulator Mode.
1. Press up on the ROCKER increase the speed in 10 knot/kph/mph increments. Press down on the ROCKER to decrease the speed in the same increments. 2. Press left and right on the ROCKER to steer the boat.
To adjust the simulated speed and heading from the Compass or Highway Pages:

Adjusting the Backlight

The Sounders adjustable screen backlighting is controlled with the POWER key, and can be adjusted from any page. To enter a simulated speed and heading from the Main Menu:
1. Press MENU twice to show the Main Menu. 2. Use the ROCKER to highlight the Systm tab, press right then down until the eld below the word Speed is highlighted, then press ENTER. 3. Use the ROCKER to enter a speed, and press ENTER. 4. Use the ROCKER to highlight Track Control. Press ENTER, and select a heading. 5. Press ENTER to nish, and QUIT until you return to the Map Page.

Entering Data and Selecting Options
To select an on-screen button:
Some pages contain on-screen buttons. As shown below, the New Waypoint Page has three buttons: Map, Delete, and OK. To start, highlight the a button, and press ENTER.
To select an optional feature:

On-Screen Buttons

BASIC OPERATION > USING THE MAP POINTER

Using the Map Pointer

To pan the map:
Working from the Map Page centers around the use of the pointer. Controlled by the ROCKER, the pointer is used to pan to map locations, mark and edit waypoints and routes, and review position data of on-screen map items and waypoints. When you move the pointer over a map item, a highlighted description of that item appears.
1. Use the IN/OUT keys to select a map zoom range. 2. Use the ROCKER to move the pointer. A data eld appears at the top of the screen showing the bearing and distance from your boat to the pointer, along with the latitude/ longitude of the pointer. 3. Press QUIT to re-center your boat on the Map Page.

Distance Bearing

Current location
Pointer Coordinates Map Pointer

Map Zoom Range

The Map Page actively scrolls or pans enabling you to explore areas around the world and create waypoints and routes. Pressing QUIT returns the map to your present location.
NOTE: When the pointer reaches the edge of the map, the unit can pause as it loads new map data.
BASIC OPERATION > CREATING AND USING WAYPOINTS
Creating and Using Waypoints
The Garmin GPSMAP 198C Sounder stores up to 3,000 alphanumeric waypoints with a user-dened symbol, comments, and depth available for each waypoint. Waypoints can be created using two basic methods: ENTER/MARK Keymarks your present location, and provides options to select a map position or map item from the Map Page. Also, you can enter a new waypoints location coordinates manually. Graphicallydenes a new waypoint location from the Map Page using the ROCKER.
The GPSMAP 198C Sounders ENTER/MARK key quickly captures your present location to create a new waypoint. The unit must have a valid position (2D or 3D) x to mark your present location. You can also use this option to manually enter waypoint coordinates.
1. Press and hold ENTER/MARK until the New Waypoint window appears. A default three-digit name and symbol are created for the new waypoint. 2. To accept the waypoint with the default name and symbol, highlight OK, and press ENTER/MARK. 3. To enter a different name, highlight the name eld, and press ENTER/MARK. Use the ROCKER to enter the new letter/numbers, and press ENTER/MARK when nished. You can use up to 10 characters for the name. 4. To select a different symbol, highlight the symbol eld to the left of the name, and press ENTER/MARK. Use the ROCKER to highlight the new symbol, and press ENTER/MARK.

Understanding Distress Calls
When the GPSMAP 198C Sounder receives a Distress Call from a connected DSC enabled VHF radio, an alert message and notication page are shown, and an alarm tone is sounded. Distress Calls are shown in the DSC Call List, and Log with a checkered symbol.
Understanding Position Reports
A Position Report is similar to a Distress Call except no alarm is sounded. Position Reports are not broadcast to all DSC users and are shown with a boat symbol.
When a Distress Call or Position Report is placed in the Call List and Log, the information on the Notication Page is retained. To review a DSC call or log entry, highlight the entry and press ENTER. The DSC Entry Review Page is identical to the Notication Page with one exception, the entry can be deleted.
Each time you receive a Distress Call or Position Report, a Notication Page is shown, and the call is placed in the DSC Call List and Log. The Notication Page contains information about the call including: the type of call (distress or position report), the MMSI number of the caller, a user denable name, the time and date of the call, the Bearing and Distance from your current position, and the coordinates of the caller. To see the callers location on a map, select the Show Map button. To create a waypoint at the callers location, select the Create Wpt button. To close the Notication Page, press QUIT.

Receiving DSC Calls

DSC Entry Review Page
1. Press Menu twice. 2. Open the Call List or Log from the DSC tab. 3. Press up or down on ROCKER to highlight the call you want to review. 4. Press ENTER to open the DSC Entry Review Page.
To review a call or log entry:
DSC Call List The DSC Call List shows the 50 most recent calls, even if the unit is left unattended. The Call List shows the most recent call from a vessel. If a second call from the same vessel is received, it replaces the rst call in the Call List. Press MENU to sort the list and delete entries. DSC Log When DSC calls are received, they are automatically placed in the Log, with the most recent call at the top. The unit can log up to 100 calls. When 100 calls are logged, the oldest log is removed when a new call is received. Press MENU to sort the list and delete entries. DSC Directory The DSC Directory acts much like a phone book and can hold up to 50 entries. Pressing MENU from this page shows options to add a New Item, Delete a highlighted entry, or Delete All entries. To add a new Directory entry:

1. Press MENU. 2. Use the ROCKER to highlight an option, and press ENTER. For detailed instructions on changing the data elds and layout of the Compass Page, see page 31.
MAIN PAGES > HIGHWAY PAGE
Numbers Page shown with middle data eld split into four elds
The GPSMAP 198C Sounders Highway Page provides graphic steering guidance to a destination waypoint, placing greater emphasis on the straight-line course, and the distance and direction you are off course. As you head toward your destination, the middle of the screen provides visual guidance to your waypoint on a moving graphic highway. Your present location is at the bottom center of the Highway Page. The line down the middle of the highway represents your course. As you navigate toward a waypoint, the highway movesindicating the direction you are off course. To stay on course, steer toward the center of the highway.
1. Press MENU, then press ENTER. Highlight the data eld, and press MENU. 2. Highlight Split Numbers, then press ENTER. Four new data elds appear. Press QUIT to nish. 3. To return to the original conguration, repeat steps 1 and 2, but instead of Split Numbers, select either Merge Numbers or Defaults. Press QUIT to nish.

To split the data elds:

Steer toward the center of the highway or towards the black vertical bar on the compass ribbon to get back on course.
The four data elds at the top of the page provide additional userselectable guidance information. Additionally, a compass ribbon shows your current heading along with a dark, vertical bar that indicates the direct bearing to the navigation point. When the dark, vertical indicator (or arrow) lines up with the lighter red bar in the middle, you are heading directly to the navigation point. Use the Highway Page as your primary navigation page in lieu of the Compass Page when your main concern is following a dened course.
Current Waypoint Data Fields Course
You can zoom in or out on the Highway Page for a smaller or larger view. Five available settings range from 1X to 16X, with a default setting of 8X. The current zoom range appears in the bottom right of the screen. To zoom in or out on the Highway Page:
Press either the IN or OUT key to increase or decrease the zoom range.

Highway Page Options

The GPSMAP 198C Sounders Highway options page denes the data elds and selects the waypoints and tracks shown. The data window, located at the top of the page, provides a user-selectable layout of various types of data. Each data eld can be congured to show several data options. The data window layout can be congured to show additional data elds and change the size of the data shown. To show and select the Highway Page options:

Route List Menu

1. From the Route Review Page, highlight the name eld, and press ENTER to begin editing. 2. Use the ROCKER to enter a name. Press ENTER when nished.
When you are on the Route Review Page, you can review the route points (waypoints or map items) one at a time from the list. To review individual route points:
1. Highlight a point, and press ENTER. 2. On the waypoint review window, you can choose Next (highlight the next point on the route list), Show Map (show the point on a map window), or Delete (permanently delete the waypoint from the unit), and press ENTER.
Route Review Menu Options
Menu options available from the Route Review Page are Edit on Map, Add Before, Remove, and Trip Planning.
When you are back on the route point list, the next point in the route is automatically highlighted. This allows you to review each point on the route by pressing ENTER repeatedly.
Highlight a point, and press ENTER to review it.
Route Review Options Menu GPSMAP 198C Sounder Owners Manual 55
Edit on Mapallows you to review and modify the route shown for each point (waypoint or map item) on a map page. Use the pointer to insert a new route point on a route leg, review the waypoint, or map item. To edit the route on the map:
From the Route Review Page, press MENU, highlight Edit on Map, and press ENTER. Use the ROCKER to highlight a route waypoint, and press MENU.

To edit a route point:

To review a route point:
1. Select the rst (to add waypoints to the beginning of the route) or last (to add waypoints to the end of the route) route waypoint with the map pointer, and press MENU. 2. Highlight the Add option, and press ENTER. 3. Move the pointer to the new point or location, and press ENTER. 4. If you are not inserting an existing waypoint, press ENTER to conrm the new waypoint. 5. Repeat steps 3 and 4 to insert additional waypoints, or press QUIT to nish.
To add turns at the beginning or end of the route:
Highlight the point, and press ENTER. Press ENTER again when nished.
The GPSMAP 198C Sounders route edit mode also allows you to insert a new route waypoint in any route leg using the map pointer. To insert a new waypoint between two existing route waypoints:
A menu of editing choices appear, with options for removing, moving (user waypoints only), or adding turns to the beginning or end of the route. To remove a route waypoint: To move a route waypoint:

MAIN MENU > UNITS TAB

Units Tab
The Unit tab denes the Position Format, Map Datum, Heading, Distance, Speed, Elevation, Depth, and Temperature units. The following settings are available: Position Formatchanges the coordinate system. You should only change the position format if you are using a map or chart that species a different position format or want to use a format you are familiar with. For additional information on Loran TD setup, see page 109.
NOTE: The Units tab settings affects how navigation information appears on the GPSMAP 198C Sounder. When in doubt, seek assistance. If you are using a map or chart in conjunction with your GPS, make sure the settings under the Units tab of the GPSMAP 198C Sounder match that of the map or chart. This information should appear somewhere on the map or chart. If the information is not present, contact the map or chart maker to determine what position format, datum, heading and units of measure are being used for the map or chart.
Map Datumsets the datum reference used to determine a given location. The default setting is WGS 84. The unit automatically chooses the best datum depending on your chosen position format. Datums are used to describe geographic locations for surveying, mapping, and navigation. You should only change the datum if you are using a map or chart that species a different datum.
WARNING: Selecting the wrong map datum can result in substantial position errors. Unless otherwise specied by the navigation documentation you are using, use the default WGS 84 datum for best overall performance.
Headingselects the reference used in calculating heading information. You can select from Auto Mag Var, True, Grid, and User Mag Var. Auto Mag Var provides magnetic north heading references that are automatically determined from your current location. True provides headings based on a true north reference. Grid provides headings based on a grid north reference (and is used in conjunction with the grid position formats described on page 70). User Mag Var allows you to specify the magnetic variation at your current location and provides magnetic north heading references based on the variation you enter.
1. With the Heading eld set to User Mag Var, highlight the heading reference eld (immediately to the right), and press ENTER. 2. Use the ROCKER to enter the magnetic variation at your current location and press ENTER. WARNING: If User Mag Var is selected, you must periodically update the magnetic variation as your location changes. Using this setting, the unit does not automatically calculate and update the magnetic variation at your present location. Failure to update this setting can result in substantial differences between the information shown on your unit and external references, such as a magnetic compass.

To mark an underwater waypoint:
Show/Hide Numberstoggles showing/hiding the data elds on the Sonar Page.

Show Numbers Option

Change Numbersallows you to specify the type of data shown in each data eld. For detailed instructions on changing the data elds, see page 31. Size Splitenables width adjustment of the Sonar Page split screen. This option is available only when a split screen zoom scale is selected. You can adjust the size of the split window anywhere from 1/4 to 3/4 width of the right half of the Sonar Page.
USING SONAR > SONAR TAB OPTIONS

Double-Arrow

Size Split Menu Options
Fish Symbolsallows you to determine how the graph shows underwater targets and background information. If sh symbols are set to Off, the unit shows all available information about the underwater environment. If a sh symbol is selected, the graph shows only the information related to that symbol. Actual sh returns can not always appear as perfect arches (like in Simulator Mode), due to the speed, sh orientation, or other conditions.
Fish Symbols Off All available information is shown. Suspended targets show as sh symbols. Background information is shown. Same as above with the target depth attached. Suspended targets show as sh symbols. No background information is shown. Same as above with target depth attached.
Resizing the Split Sonar Page

Sonar Tab Options

1. Press MENU twice to access the Main Menu. Use the ROCKER to highlight the Sonar tab. 2. Using the ROCKER, highlight the eld, and press ENTER. 3. Highlight the setting, and press ENTER. 4. Press QUIT to return to the Sonar Page or a previous page.
To access and change a setting on the Sonar tab:
Water Typebecause sound waves travel through fresh and salt water at different rates it is necessary to select the water type to ensure accurate readings on the unit.
Depth Numbercontrols the efciency of the digital depth update rate. Fast Update updates more quickly and is recommended for low-noise, deeper water (>50 ft) Auto is best for shallow water or high noise areas, and produces a slower screen update. Use Auto when you travel a wide variety of depths.
NOTE: If the unit is unable to track the bottom for any reason, the digits in the depth window ash on and off to alert you that the unit is not tracking the bottom.
Color Barshows a gradient scale of the current Target Level setting (see page 81).

Tree Sonar Page 89

Aerial View of the Water GPSMAP 198C Sounder Owners Manual
USING SONAR > UNDERSTANDING SONAR

Transducer Coverage

The area covered by the transmitted sound waves is determined by the cone angle of the transducer and the water depth. The wide cone angles (40) associated with low frequencies (50 kHz) provide a large coverage area for nding sh within a coverage width that is approximately 2/3 of the water depth. However, this also means that wide cone angles produce less bottom detail and resolution. As shown in the drawing on the near right, the 40 cone angle produces a coverage area of approximately a 20-foot diameter circle at a 30-foot depth. The narrow cone angles (10) associated with the high frequencies (200 kHz) provide better bottom resolution and crisper detail, but cannot show a large coverage area for nding sh. The 10 cone angle provides a coverage width that is approximately 2/10 of the water depth. As shown in the drawing on the far right, the 10 cone angle produces a coverage area of approximately a 6-foot diameter circle at a 30-foot depth. Dual frequency mode combines both frequencies to get the best coverage area and contour/depth readings.

Coverage Diameter

Depth Coverage Diameter

40 Cone Angle (50 kHz)

10 Cone Angle (200 kHz)

Whiteline

When the sonar sound waves are reected back by the bottom, a hard bottom returns a stronger signal than a soft bottom. A thin whiteline indicates a softer bottom, while a thick whiteline indicates a harder bottom. Normally, a red line is used to show the point where water meets the bottom. This line follows the bottom contour, along with any signicant objects lying on the bottom. The unit uses the whiteline function to make the bottom layer information easier to distinguish.

Thermoclines

A rough denition of a thermocline is a break in water where the water temperature changes faster than the water above it. Thermoclines are shown as the weakest colors. One of the unique features offered by Garmin is See-Thru technology, which allows the GPSMAP 198C Sounder to hear both weak and strong signals simultaneously so as to identify sh returns under the toughest conditions, such as suspended in thermoclines or even hiding near structures. See-Thru technology allows the transducer to see through thermoclines and locate sh.

Thick Whiteline: Hard bottom

Whiteline On

Whiteline Off

Thermocline

APPENDIX > SPECIFICATIONS

Specications

APPENDIX

Physical Specications

Weight: Less than 2.0 lb
Size: 6.2" H x 6.30" W x 3.7" D (15.7 cm x 16.0 cm x 6.7 cm) Display: 5.0" diagonal (12.7 cm) 16-color TFT display with backlighting (234 x 320 pixels) Case: Fully gasketed, high-impact plastic alloy, waterproof to IEC 529-IPX-7 Temp. Range: 5F to 158F (-15C to 70C)
DGPS (USCG) Accuracy: Position: 3-5 meters (10-16 feet) with optional Garmin DGPS receiver, 95% typical* Velocity: 0.05 meters/sec steady state DGPS (WAAS) Accuracy: Position: <3 meters (10 feet), 95% typical* Velocity: 0.05 meters/sec steady state Dynamics: 6gs * Subject to accuracy degradation to 100 m 2DRMS under the U.S. DOD-imposed Selective Availability Program.

Performance

Receiver: Differential-ready 12 parallel channel WAAS capable receiver Acquisition Times: Warm: Approx. 15 seconds Cold: Approx. 45 seconds AutoLocate: Approx. 2 minutes Update Rate: 1/second, continuous GPS Accuracy: Position: <15 meters (49 feet), 95% typical* Velocity: 0.05 meters/sec steady state
Source: 10-32 V DC Usage: 14 watts max. at 13.8 vDC Fuse: AGC/3 AG-3 Amp
Sounder Power: 500 watts (RMS) 4000 watts (peak to peak) Frequency: 50/200 kHz (40/10) Depth: 1500 foot max depth*
* Depth capacity is dependent on water salinity, bottom type, and other water conditions.
APPENDIX > INSTALLING THE GPSMAP 198C SOUNDER
Installing the GPSMAP 198C Sounder
The GPSMAP 198C Sounder must be properly installed according to the following instructions to get the best possible performance. To complete the installation, you need the appropriate fasteners and a 1" x 14-thread marine antenna mount available at most marine dealers.

Mounting the GPS Antenna

Suggested locations for mounting the external 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. Avoid mounting the antenna where it is shaded by the boats superstructure, a radome antenna, or mast. Sailboat users should avoid mounting the antenna high on the mast to prevent inaccurate speed readings caused by excessive heeling. Most marine VHF and LORAN antennas should not seriously degrade the GPS antennas reception. Never paint the antenna or clean it with harsh solvents.

The Garmin antenna screws directly onto any standard 1" x 14thread antenna mount. If you need to raise the antenna to avoid shading, try using a 1" x 14-thread extension mast available at most marine dealers.
NOTE: It is possible to route the coaxial cable either through, or outside the antenna mount. It is possible to remove the BNC connector on the coaxial cable and the coaxial cable shortened to ease installation, however, doing so voids the antenna warranty. If the BNC connector is removed, it must be replaced with a new solder-on or crimp BNC connector.
APPENDIX > MOUNTING THE GPSMAP 198C SOUNDER 1. Screw the antenna directly onto the 1" x 14-thread mount. 2. Route the cable to the mounting location of the unit. Use the appropriate tie-wraps, fasteners, and sealant to secure the cable along the route and through any bulkhead or deck. 3. After the GPSMAP 198C Sounder unit is installed, connect the cable to the antenna connector on the back of the unit. Make sure that you turn the antenna cable connector 1/4 turn clockwise to lock the cable into place.
To install the GPS antenna:
Mounting the GPSMAP 198C Sounder

Using the Gimble Mount

The GPSMAP 198C Sounders compact, waterproof 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 or overhead mounting. When choosing a location for the unit, consider the following conditions: There should be at least a 3" (7 cm) clearance behind the case to allow connection of the antenna and power/data cables. The mounting surface should be heavy enough to support the unit and protect it from excessive vibration and shock.
NOTE: The temperature range for the GPSMAP 198C Sounder is 5F to 158F (-15C to 70C). Extended exposure to temperatures exceeding this range (in storage or operating conditions) can cause failure of the screen. This type of failure and related consequences are NOT covered by the manufacturers limited warranty.
APPENDIX > MOUNTING THE GPSMAP 198C SOUNDER 5. Screw the two mounting knobs through the bracket and into the screen case. 6. Connect the power/data and antenna cables (external antenna only) to the back of the unit, making sure the locking rings are fully tightened on both connectors.
Flush Mounting the GPSMAP 198C Sounder
The GPSMAP 198C Sounder can be ush mounted on a at panel. When ush mounting the GPSMAP 198C Sounder, be sure to choose an appropriately sized location for the unit (see unit dimensions on page 93) and leave 1.25" (32 mm) clearance below the data card slot for inserting or removing data cards. A Flush Mount Template is provided in the package. Use the instructions on the template to complete the ush mount installation.

1. Select a location for the mounting bracket. 2. Mark and drill the four mounting holes for the fastener you are using. 3. Fasten the bracket to the surface using the appropriate fastener. 4. Insert the GPSMAP 198C Sounder into the mounting bracket. The bracket is designed for a tight t to provide additional support when swiveling the unit.
To install the GPSMAP 198C Sounder:
APPENDIX > INSTALLING THE TRANSDUCER
Installing the Transducer
The transducer acts as the eyes and ears of your new sonar. Proper transducer installation is critical to the operation of your unit. The transducer transmits sound waves toward the bottom in a cone shape. The larger the cone angle, the larger the coverage area at a given depth.
A wide cone angle transducer works best in shallow water. The wide cone angle provides a large coverage area, but at a decreased bottom resolution. In deeper water this can result in a large dead zone where sh cannot be seen. A narrow cone angle transducer is better suited to deep-water installations. The narrow cone angle provides a smaller viewing area (compared to a wide cone angle transducer at the same depth) with improved bottom resolution and a smaller dead zone. Dual frequency transducers give you the best of both wide and narrow cone angles. A 50/200 kHz dual frequency 40/10 cone angle, temperature sensing, transom mount transducer is included in the GPSMAP 198C Sounder (with transducer) package. This transducer provides good all-around performance.

Wide cone angle

Narrow cone angle

dead zone fish not seen

Transom Mount Transducer
The following diagram is for mounting the transducer included with the GPSMAP 198C Sounder with transducer package. If the transducer lead is too short, extension cables are available from your Garmin dealer. DO NOT cut the transducer lead or any part of the transducer cable, as this will void your warranty. The cable cannot be spliced and connected to any existing (Garmin or non-Garmin) transducer cables.
NOTE: DO NOT mount the transducer behind strakes, struts, ttings, water intake, or discharge ports, or anything that creates air bubbles or causes the water to become turbulent. It is important that the transducer is in clean (non-turbulent) water for optimal performance.
Apply marine sealant to all screw threads to prevent water from seeping into the transom.
Mount the transducer cable cover well above the waterline.
Transducer should extend 1/8" below fiberglass hull or 3/8" below aluminum hull
Make sure that the transducer is below water level when the boat is on plane at high speed Do not mount transducer directly in the path of the prop. The transducer can cause cavitation that may degrade the boat's performance and damage the prop.
Mount the transducer parallel with the bottom.
APPENDIX > CARE INFORMATION

APPENDIX > INSTALLING AND REMOVING DATA CARDS
Installing and Removing Data Cards
The GPSMAP 198C Sounder uses optional Garmin marine BlueChart and MapSource data cards to show digital charts and maps on-screen. Data cards are installed in the card slot located at the bottom right of the unit. Data cards can be installed or removed at any time, whether the unit is on or off.
1. Open the card door by pressing together on the two handles at the bottom of the door and lifting it up and open. 2. Insert the card, with the label facing front and the handle bottom, into the slot. 3. Firmly push the card into the unit. It in not necessary to force the card and about 1/2" is still exposed when it is properly inserted. If the unit is on, a conrmation tone sounds and a message shows on-screen noting the card details when the card is properly installed and accepted. 4. Close the cover.
1. Open the card door by pressing together on the two handles at the bottom of the door and lifting it up and open. 2. Grasp the card handle at the bottom and pull down rmly. 3. If the unit is on, a conrmation tone sounds when the data card has been removed.

To remove a data card:

To install a data card:
If you insert a data card and get a card format not recognized message, try removing the card and reinserting it. If the card is still not recognized, contact Garmin Support or your Garmin dealer for assistance. Data cards are not waterproof and should not be exposed to moisture or excessive static charges. Data cards should be stored in the case supplied with the card.
The rst time you insert a data card, the unit takes a few seconds to read the card. After the data card is read, a summary screen appears. Press ENTER to acknowledge.
APPENDIX > SATELLITE INFORMATION

Satellite Information

Satellite Strength Indicator Bars
Center dot - 90 above the horizon
Inner ring- 45 above the horizon Outer ring the horizon
The Satellite Strength Indicator Bars show the strength of the signal being received, and the status of the signal. The bars are either shaded or lled. The gray bar means the GPS is in the process of storing orbital data it is receiving from the satellite signal. When the bar turns solid, the GPS is using the satellite signal for navigation. A D in or above the bar means that differential corrections (WAAS or DGPS) are being applied to that satellite.

Satellite Sky View

Date, Time, and Current Location

Satellite Location

The location of each available satellite shows over two location rings on the Satellite Information Page. The outer ring represents the horizon, the inner ring represents 45 above the horizon, and the center represents directly overhead. When the unit is using a satellite for navigation, the satellite number is highlighted on the location rings. The unit can be set to show satellite location with North or your current track at the top of the screen.