I install Dish Network and DirecTV on Houseboats all the time.. Not sure about regular boats as they probably move to much.. Most Houseboats are stabilized to the shore pretty good. Up and down as the water rises has no effect on the dish.. The only issue would be side to side and as most Houseboats I see here have front and back stabilizer poles I don't have an issue.. Rocking occurs somewhat, but usually within the tolerance of the dish it has little effect also.. I would rather mount to the dock itself if I can, but I have never had a customer complain about one that was actually mounted to the houseboat itself.