Garmin GPS 188C Manual

The Garmin GPS 188C is a high-performance, waterproof marine GPS chartplotter featuring a high-resolution color TFT display, built-in worldwide basemap, detailed marine cartography compatibility, external antenna, NMEA 0183 interface, track plotting, waypoint management, MOB (Man Overboard) function, and robust navigation tools. Designed for marine use, it operates on 12-24V DC. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Waterproof housing, Color TFT display, External GPS antenna, Power/data cable, NMEA 0183 interface, Card slot for detailed charts.

Feature	Description
Display	High-resolution color TFT, sunlight readable
GPS Receiver	12 parallel channel, WAAS enabled
Waterproof Rating	IPX7 (submersible 1 meter for 30 minutes)
Chart Compatibility	Accepts Garmin BlueChart and MapSource cards
Waypoints/Routes	500 waypoints, 20 reversible routes
Tracks	10,000 point automatic track log
NMEA 0183	Interface for autopilot, instruments, etc.
MOB (Man Overboard)	Instant mark and navigation to position
Backlight	Adjustable for night viewing
Power Input	12-24V DC, typical marine electrical system

Installation

Unpack and inspect contents. Choose mounting location carefully.

1. Mount the unit: Select a location with clear view of sky for antenna and easy viewing. Use mounting bracket and hardware provided.
2. Install external antenna: Mount antenna with clear 360° view of horizon; connect cable to unit.
3. Connect power: Connect red wire to positive (+), black wire to negative (-) of 12-24V DC source. Use in-line fuse as recommended.
4. Connect NMEA devices: If interfacing with autopilot or other instruments, connect NMEA 0183 wires per diagram.
5. Insert chart card: Power off, insert compatible Garmin chart card into slot.

WARNING! Ensure all connections are waterproofed. Disconnect power before making connections. Follow marine electrical standards.

First-Time Setup

Apply power; unit will initialize.

1. Acquire GPS signal: Place unit with clear sky view. Initial fix may take several minutes.
2. Set language and units: Press MENU, go to Setup > System. Select language (ENGLISH default), set units (nautical miles, knots, etc.).
3. Calibrate compass (if applicable): Follow on-screen prompts if unit has electronic compass feature.
4. Configure chart display: Press MENU, go to Chart setup. Adjust detail, depth shading, and colors.
5. Set alarms: Configure anchor drag, arrival, and off-course alarms in Alarms menu.

CAUTION! Ensure secure mounting before vessel movement. Verify GPS fix before navigating.

Specifications

• Display: Color TFT, sunlight readable.
• GPS: 12 parallel channel, WAAS/EGNOS capable.
• Waypoints: 500 with name and symbol.
• Routes: 20 reversible routes.
• Track Log: 10,000 points, automatic.
• Interface: NMEA 0183 input/output.
• Waterproof: IPX7 standard.
• Power: 12-24V DC, 1 Amp max.
• Operating Temp: -15°C to 70°C.
• Dimensions: Refer to product datasheet.

Controls and Settings

Front Panel: POWER key, PAGE/ROCKER key (up/down/enter), QUIT/MOB key, IN/OUT zoom keys.

On-Screen Menus: Accessed via PAGE or MENU keys. Main pages: Chart, Highway, Navigation Data, Trip Computer.

Settings Menu: System (Language, Units, Time), Chart (Detail, Shallow/Deep Water), Alarms (Anchor, Arrival), NMEA (Baud rate, sentences), Tracks & Routes.

Quick Functions: MOB (Man Overboard) - press and hold QUIT/MOB key. Mark Waypoint - press ENTER on rocker key.

Connecting Devices

NMEA 0183: Connect to autopilot, sounder, or other instruments for data exchange.

1. Turn off all devices before connecting wires.
2. Identify NMEA In/Out wires on GPS 188C cable (typically blue, brown, etc.).
3. Connect GPS NMEA Out to instrument NMEA In, and GPS NMEA In to instrument NMEA Out.
4. Set correct baud rate (4800 default) in NMEA setup menu.
5. Power on and verify data flow.

Tip: Use shielded cable for NMEA connections and keep away from power cables to reduce interference.

Navigation & Chartplotting

Follow your position on the detailed chart.

1. View Chart Page: Default display shows boat icon on chart.
2. Zoom: Use IN/OUT keys to change chart scale.
3. Pan: Use rocker key to move cursor around chart; press ENTER to recenter on cursor.
4. Navigate to Waypoint: From Waypoint list, select waypoint and choose "Go To". A direct course line appears.
5. Follow a Route: Activate a saved route from Route list. Legs of the route are displayed.
6. Highway Page: Provides steering guidance with pictorial "highway" view.
7. Data Pages: View speed, course, bearing, distance, ETA, and cross-track error.

WARNING! Always use charts in conjunction with traditional navigation methods. GPS is an aid to navigation.

Waypoints & Routes

Create and manage waypoints and routes for trip planning.

1. Mark Waypoint: Press ENTER on rocker key at current position. Edit name and symbol.
2. Create Waypoint at Cursor: Move cursor to desired spot, press ENTER, select "New Waypoint".
3. Edit Waypoint: Select from list, choose "Edit".
4. Create Route: Go to Route menu, select "New". Add existing waypoints in sequence.
5. Navigate Route: Select route, choose "Navigate".
6. Track Log: View and save track history. Can be converted to a route.

MOB Function: In emergency, press and hold QUIT/MOB key. Instantly marks position and begins navigation back to that spot.

Care & Maintenance

Use fresh water and mild soap to clean exterior. Do not use harsh chemicals or abrasives.

CAUTION! Ensure power is disconnected before cleaning connectors. Keep card slot cover closed when not in use. Store in a dry place.

Regulatory Information

FCC Compliance: This device complies with part 15 of the FCC Rules. Operation is subject to the condition that it does not cause harmful interference. Contains GPS technology subject to U.S. export laws. © Garmin Ltd. or its subsidiaries. Garmin and the Garmin logo are trademarks of Garmin Ltd. or its subsidiaries. For support, visit www.garmin.com/support or contact Garmin Product Support.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No Power	Blown fuse, loose connection	Check in-line fuse; verify secure power connections at unit and battery.
No GPS Fix	Antenna obstructed, poor signal	Ensure antenna has clear sky view; wait longer for initial fix; check antenna cable.
Inaccurate Position	Poor satellite geometry, old almanac	Allow unit to receive signals undisturbed; ensure WAAS/EGNOS enabled in settings.
Chart not displayed	Card not inserted, incompatible	Ensure chart card is fully inserted; verify card is compatible Garmin format.
No NMEA data	Incorrect wiring, wrong baud rate	Check NMEA connections; verify baud rate matches connected device (usually 4800).
Dim display	Backlight setting	Adjust backlight level in System settings.

Reset: System menu > Reset to Factory Defaults (note: erases all user data).

Service: Contact Garmin Product Support or authorized service center. Do not open unit.