  The GPSMAP 172C fixed-mount chartplotter offers brilliant sunlight-readable color LCD, robust features, and a user-friendly interfacein a compact, value-priced console. It comes standard with a built-in worldwide marine basemap and accepts MapSource® BlueChart® offshore marine cartography—featuring detailed depth contours, inter-tidal zones, wrecks, navaids, and many other points of interest. For small-water anglers, the GPSMAP 172C is compatible with MapSource Recreational Lakes with Fishing Hot Spots—featuring fishing areas, boat ramps, marinas, and hazards for hundreds of popular U.S. and Canadian lakes. Pre-programmed data cards can be easily inserted into the slot on the front of the unit. The GPSMAP 172C also has all the features you would expect from Garmin; a 12 channel WAAS receiver for accuracy up to 10 feet, simple operation, audible alarms, celestial tables and much more. One year Warranty. For added flexibility, mariners can upgrade the GPSMAP 172C to a full-fledged combination chartplotter/sounder at any time by adding a Garmin® GSD 20 "black box" sonar and transducer. Size: 6.3"W x 4.9"H x 3.7"D.
*The WAAS signal is currently available in the US only in open areas or on the water. | 
WAAS enabled 12 channel GPS receiver for accuracy of up to 10 feet.