Good question..... I was wondering that to . I have a garmin CSi 60 handheld I use at coalcreek Tn when riding my SXS, I was thinking about using. But it has a small screen, eats batteries also. I have to keep it plugged in to a 12 volt source, it can be hard mounted in a clip in your boat. It works great I have over 150 thuosand acres of trails mapped out in it. Dont know how the small screen would effect you on the water. Hope some more peeps will pipe in.....