How can I navigate a car with GPS?

I want to buy a GPS device. I want to use it to navigate on my boat, and to navigate in my car. Is there a single device that does both (without buying more stuff)?

• Answer:

  You can do both on a single GPS. In a broad sense, all a GPS does is find your location then plot it against a map. All GPS units can find location, its just a question of what maps you have to plot against. If you can load detailed maps of both land and sea into a single GPS unit, it will serve just fine. For example, the Garmin GPSMAP series is set up for Marine use. For nautical purposes, it comes with a pre-loaded basemap of waterways. It also comes with a basemap for land use that includes major highways, interstates, and cities. If you want more detailed marine maps they offer their BlueChart software to upload marine maps with more detail to your GPS. They have similar software for more detailed land maps, called MapSource. So long as your GPS accepts SD cards for storage, you can put just about all the maps you'll ever need for land and sea on one GPS.