Garmin GPSMAP 378

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Questions and Answers (Q&As)

What's Included In The Box?

• GPSMAP 378 Receiver
• Preloaded U.S. Inland Lakes
• Preloaded City Navigator NT North America (full coverage)
• Garmin Trip and Waypoint CD (View this item)
• Garmin USB PC Interface Cable (View this item)
• Garmin GPSMAP 276C and 296 Bare Wire Power Data Cable (View this item)
• Garmin GPSMAP 276C 296 Marine Mount (View this item)
• Garmin GPSMAP 176C and 276C Auto Mount (View this item)
• Universal Non Skid Friction Mount
• Garmin GPSMAP 276C and 296 Cigarette Lighter Adapter (View this item)
• Garmin GPSMAP 276C and 296 AC Adapter (View this item)
• Garmin GPSMAP 276C Lithium Ion Battery (View this item)
• Garmin Protective Cover GPSMAP 276C (View this item)
• Owner's Manual
• Quick Reference Guide

Product Information

Gallery of Customer Images

Customer Reviews

Family Series

Manufacturer Description

Go from box to boat to dash with the portable and versatile GPSMAP 378. This combination color chartplotter and land navigator comes preloaded with maps for lakes throughout the continental U.S., in addition to detailed North America street-level mapping. Optional weather and sonar capabilities combined with the ability to conveniently add plug-in data cards, let you easily add more maps and features — making this one incredible GPS navigator for land and freshwater.

Preloaded and Portable
From curbside to dockside, the GPSMAP 378 has you covered — no downloads or computer required. Its preloaded inland lake maps boast 10-meter resolution for more than 3200 lakes — many with depth contours. In addition, these built-in freshwater maps provide shoreline detail, river and creek channels, islands, boat ramps, campgrounds and more for tens of thousands of lakes across the continental U.S. — giving you the freedom to boat and fish anywhere in the states. These maps also show streams and rivers, tide stations and predictions, a wrecks and obstructions database, and U.S. Coast Guard aids to navigation.

For road trips, the 378 along with its saltwater counterpart, the GPSMAP 478, come preloaded with City Navigator NT detailed street maps for North America and include automatic routing with voice guidance along with an industry-leading database with more than six million points of interest — including hotels, restaurants, gas stations, marinas, attractions and more. These street maps are seamlessly integrated with the 378's lake maps. An included marine mount and automotive kit make it a snap to transfer the unit from boat to car.

Up-to-date Weather
See real-time weather displayed on the 378’s high-resolution 256-color sunlight-readable TFT display with the purchase of the GXM 30 antenna (sold separately) and subscription to XM WX Satellite Weather. View vital weather data, such as NEXRAD radar, storm cells, wind speeds, surface temperatures, forecasts and more than a dozen other weather attributes directly on the unit’s display — so you can spend more time enjoying the water and less time worrying about the weather.

With the GXM 30 antenna, you also have the option of receiving XM Satellite Radio’s 150 plus channels of commercial-free music, sports, news, talk and entertainment programming. Weather and audio options travel with your plotter, whether you’re navigating on land or sea.

Sonar Capability
If fishing’s your game, pair the 378 with the GSD 21 remote sounder module to add sonar capability. The GSD 21 is Garmin’s “black box” sounder, which offers 4,000 watts of power peak-to-peak (500 watts RMS) in a dual-frequency transducer (purchased separately).

Plug-and-play Additional Mapping
Optional software available on plug-in Garmin data cards, lets you instantly add new maps to your GPSMAP 378 — without connecting to your computer. Heading offshore? Pair the 378 with BlueChart g2 cards for exceptional offshore detail, port photos and more. Easily customize map data for your adventures on land or sea with our optional MapSource cartography.

Features and Tips

GPSMAP 378 features

• Receiver: WAAS-enabled, 12 parallel channel GPS receiver


• Display: 3.8-inch diagonal, 480 x 320 pixel, 256-color TFT screen with adjustable LED backlight


• Unit dimensions: 5.7"W x 3.2"H x 1.9"D


• Waypoints: Stores 3,000 waypoints and 50 reversible routes


• Tracks: 10,000 point automatic track log saves up to 15 tracks


• Battery life: Rechargeable lithium-ion battery offers 4 to 15 hours of use (4 hours with GXM 30 and 15 without GXM 30)


• Water resistant up to IEC 60529 IPX7 standards (submersible in one meter of water for 30 minutes)


• Preloaded inland lakes


• Built-in street navigation with voice prompts, using included cable and speaker


• Accepts the latest (optional) BlueChart g2 data cards


• Add optional GSD 21 for full-feature sonar capability


• Add optional GXM 30 antenna for XM WX Satellite Weather


• Provides tides and built-in celestial information


• NMEA 0183 input and output


• Removable quad helix antenna


• Single knob tilt/swivel mount

Specifications