I have a Garmin E-Map. I am happy with it so far. Does have decent cartography for a hand held. I just plug it into the sigaret lighter. You do need to keep this one dry as opposed to the one you mentioned in your post. I was out at Neah Bay earlier this summer in the fog, 8ft swells past Cape Flattery. The GPS definitely gives you a comfort level that wouldn't be there otherwise. The GPS also saved my bacon in the San Juans, navigating in the fog.