I have been using a Fishin' Buddy since 1996. I am on my second one which I just bought a few months ago. I have been very pleased with it and the newer one has a lot of improvements. The only problem I've had (and I use mine in the ocean all the time and beat it up pretty good) is the tips of the batteries tend to rust if you don't remove them after each trip (I tend to forget). I like it's portability.

Check out this page for instructions on how to build my Fishin' Buddy holder for float tubes:
http://leapinbass.com/fishing/tubing-gear.htm