â€" for driving paddle wheelers uphill. For going downhill on the slopes of tsunami waves, a motor would become a generator for recharging a bank of storage batteries. A better use might be in manned models of vessels with both sails and paddle wheels.
For a little help in harbors and calms, use the motor, or motors, to drive one of more paddle wheels. When the wind freshens the sails would go up and the paddle wheels would become "water wheels" for the generation of electricity. For details of this trip in a waybackmachine, go to: http://tinyurl.com/awfj7 to read about a gizmo that is already used in sailboats with electric motors and propellers for auxiliary propulsion.