Here's what I did to make it bullet proof.
1. For the below deck terminals I coated with many coats of liquid electrical tape.
2. Added Oring to male portion of plug to keep any deck wash water out of the plug.
3. Coated terminals on male plug with many coats of liquid electrical tape then filled cavity with urethane caulk, (silicon caulk and salt water make hydrochloric acid).
It's been on the boat for over a year and no signs of corrosion.
BTW did you ever get the specs on you're prop for me?