On the side of the boat make a mark/tape even with the pylon. Then measure back from there 17" and place tape there that is my minimum 35off height when coaching.
Inrush current can be up to seven times the full load current! So if you have a 1 HP motor running 16 amps @ 120 volts inrush could be 112 amps for a fraction of a second. Run the circuit and be done.