I just recently purchased a Magellan SportTrak Pro and I really love it.
I had an older Magellan that I bought used from a friend and learned how to use it by Geocaching (lots of fun, by the way). It was a fairly simple GPS. If one had coordinates, it would point you in the right direction and was fairly accurate in pinpointing the spot, but the new SportTrak Pro has so many neat features, I don't know how I got along without it.
I think I got a really good deal on mine from Costco. Came with a cord to plug into computer, cord to plug into cigarette lighter, carrying case to carry on belt, carrying device to suction cup to windshield of vehicle and software to download detailed maps of any area in the US. All this and a $75 rebate also. The instore package is a little different then the online package, which can be found
here .
I think that this little unit will work just as well on the water as it works on land. In fact, one of the features is the ability to specify "land use" or "water use". And it is water proof and it floats.
I haven't "played" around with a lot of different GPS's, but the first one I had worked really well, and my new one seems be working better then the first one.
And like some of the others have suggested, check out the Geocaching web-site
here .
Goeduck