Scott – The 172C will take data cards.
Here’s some details:
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.
320 x 320-pixel, 256-color CSTN screen with adjustable CCFL backlight
3.2″ W x 3.2″ H (4.5″ diagonal) viewing area
6.3″ x 4.9″ x 3.7″ (W x H x D) unit dimensions
State-of-the-art 200 MHz processor makes data acquisition, panning, and zooming virtually instantaneous
User waypoints are automatically tagged with the date and time of creation
10,000 active track points and 700 saved track points; waypoints, routes, and tracks can be stored on removable data cards and transferred to a PC or another unit
Sends, receives, and displays positioning data with DSC-equipped VHF radios
TracBack™ mode helps guide you back to points along a route
Tracklines can be color-coded for trolling or cruising applications
I think it will be a great unit. Let me know if you have any other questions.