Do boats float better in deep or shallow water?

Some guesses: Because fresh water is slightly less dense (slightly lower specific gravity) than salt water, a boat in fresh water will have slightly more draft; the boat will sink a little further down and possibly experience a little more stability as a result. The depth of the water probably doesn't have a lot of affect, as long as the boat doesn't touch bottom. On the other hand, very deep water can probably be much more difficult to manage in severe weather. Not really an easy question at all.