there are water proof ones out there. There is a big FAA push for more laws. They can be dangerous and the ones I have seen that may be worth it start at over a boat buck.

Another one was interesting. It had a return home feature. When I watched the video it explained that all you had to do was push the "Home" button and it would return ....... wait for it...... to the exact GPS derived spot it took off from. This might be the spot the boat is in any more!

Another one (at 2 boat bucks base price) did have an interesting "follow me" option.

Greg