Features:

• WAAS-Enabled, 12 Parallel-Channel GPS Receiver
• All-In-One Versatile, Color Chart Plotter & Vehicle Navigator¿Perfect For Land Or Water
• 3.8-Inch Diagonal, 480 X 320 Pixel, 256-Color Tft Screen With Adjustable Backlit Led
• Adjustable Marine Mounting Bracket
• Stores Up To 3,000 User Waypoints, 50 Reversible Routes (300 Waypoints Per Route)

Editor Reviews:

Product Description:
The GPSMAP 276C is a versatile color chartplotter and automobile navigator, perfect for land or water. Along with its counterpart, the GPSMAP 276C, this portable navigator features a sunlight-readable 256-color TFT display and a built-in autorouting basemap that can route you on major interstates and highways. On water, the GPSMAP 276C is a dependable color chartplotter with built-in basemap enhanced by Garmin's marine cartography. For extra-precise navigation, the 276C has a Course Deviation Indicator (CDI) - a feature normally found on aircraft, but equally practical for the marine environment. The CDI quickly indicates whether your boat has veered off-course and helps you get back on track quickly. The 276C also supports external NMEA sources for water depth, water temperature, and water speed through two serial interfaces. On land, the GPSMAP 276C's autoroute basemap can route you on interstates and major highways. The 276C is compatible with BlueChart maps, which add extra detail when you're out on the seas. It also accepts optional MapSource data cards, so you can add other types of map data easily. For convenience and easy map transfer, you can connect the 276C to your computer with the included USB cable. NMEA 0183 input/output Maps & Memory - Basemap with the ability to add maps through Garmin data cards 3000 Waypoints/favorites/locations 50 Routes 10,000 points Track log Unit Dimensions - Width 5.7 x Height 3.2 x Depth 1.9 (14.5x8.1x4.8cm) Unit Weight - 13.6 ounces (385 grams)

Amazon.com Product Description:
This WAAS-enabled, 12 parallel channel GPS receiver provides color chart plotting for both land and sea, making it an excellent addition to any boat or automobile dashboard. Its display-- 3.8-inch, 480 x 320 pixel, 256-color backlit TFT--provides enhanced sunlight-readability, and its adjustable quad helix receiving antenna with remote antenna capability delivers superior data reception.

Used with your car, the 276c's auto routing capability lets you select a destination and get turn-by-turn directions. There's even voice prompt guidance; just hook up a 12-volt speaker cable (sold separately) and the GPSMAP 276C will audibly tell you when you need to turn and how much farther you have to go.

Data provided with the unit includes 3000 user waypoints with an expanded list of waypoint symbols; 50 reversible routes with 1,200 waypoints per route; 10,000 point automatic track log with 15 saved tracks and 700 saved track points each; position formats including Lat/Lon, UTM, Loran TDs, Maidenhead, MGRS, User, and more; a large numbers option for easy viewing, and much more.

In addition to its built-in basemap detail (cities, interstates, coastline detail and US tide stations), the GPSMAP 276C accepts data from MapSource CD-ROMs, including BlueChart for offshore detail, Recreational Lakes with Fishing Hot Spots for detail of selected inland lakes, and City Select for street-level maps. The package includes the GPSMAP 276c, USB interface cable, power/data cable, marine mount, Trip & Waypoint Manager CD, rechargeable lithium-ion battery, AC adapter, owner’s manual, and a quick reference guide. Manufacturer rating of the battery lists it at up to 15 hours of use depending on backlight setting.

Rating : - I was not impressed.
This claims to be "perfect for land or water" in its description, but that is not the case at all. I took this deep-sea diving (I was hunting for monsters), and as soon as I got underwater the unit completely stopped working! I called the customer service, and they said it was "user error". Me and my new monster pets are very upset.