Did it 20 years ago install a small motor with drive shaft in the float that has no rudder on it the prop sticks out about 1/2 inch hook up to switch and two 1.5 V dry cells to make 3V AA's work good Working on a new set up Hobby Lobby sells a folding prop for sail boats that way there is no prop drag Also putting one in the hull of sea plane comes out of step has small cut out in hull bottom like half moon so when blades open they wont hit the hull but are flush with the bottom when folded so they dont hang up on anything also will work on float step if you do not want it at the back of float