Don't let this dissuade you from using this device for marine use, consider it for on-road and recreational use on land. In fact, this device's water resistance and buoyancy amplify its already impressive performance for hikers, cyclists and car enthusiasts. It uses all kinds of MapSource software and offers the possibility of using street, topographic and nautical maps. Removable storage allows users to expand storage capacity or create memory cards preloaded with select decks of cards. I installed the 2GB map and loaded all available MapSource maps east of the Mississippi including parts of Canada, the Isthmus of Mexico and Caribbean world maps! I no longer have to sit down and select maps for my next trip and download them to my device. I also don't have to download map segments on long trips during the trip (which required my computer). It is there! This is almost as good as the DVD method used in today's automotive embedded systems in terms of map storage. It is much better than car systems in terms of features, portability, flexibility and so on. No movement restrictions; all data can be uploaded and downloaded with a computer; If the road is on the map, this GPS will get you there - no "road unsupported by nonsense". This is the third Garmin GPS I have bought. It has several features that are superior to the GPS V I have and put the GPS12 to shame (although a very good device for its time). Track Log. Uploaded tracks can be twice as many as the GPS V and three times the total score. The satellite reception is amazing - it picks up satellites often enough to cover me even when I'm at my desk in my home office! The addition of an electronic compass and altimeter improves the usability and accuracy of an already impressive device. You will not regret the purchase!