Thanks Mike for your comments. I can not pull the 85 lb motor out of the well. Further, I have concluded (be it right or wrong) that to try to remount a motor in a heavy sea is very dangerous. I don't know how others do it safely. And as for pulling the motor out when leaving the boat, that is a big hassle, and I don't have a couple young turks standing nearby to help.

Yes the pitch is correct for a heavy load - minimum pitch, pitched for almost no forward motion at all. Actually, the pitch issue and cavitation, I think, would only arise with a low pitched prop used on a high speed/light boat. With a high pitch prop on a low speed hull, the prop would not cavitate, but, instead, the motor would not get up to speed and there would be no power. The engine appears to reach the right rpm.

The problem I don''t think is wiring (I do not hook up to the AC when in port) The entire electrical system is tied into a large copper grounding plate in the water near the keel. The zinc anode on the outboard just above the prop should discharge any currents relevant to the motor (and yes, it is eaten away). As for powerboats nearby in the marina, yes there are tons of the floating kitchens. However, I can't really control other people's wiring. Further, I visit various marinas during the summer.

Keep in mind that this problem is not just related to my set-up but is related to all outboards. The problem is discussed in the Interlux brochure, and outboard motor instruction manuals. It appears to be universal. Everyone says that if the motor is left in the water, the lower unit and the prop must be protected by some sort of supplementary finish. It may not be electrolysis but simply corrosion of the aluminum. It may be that the movement of the prop, or the motor through the water creates a static charge that eats up the prop. I don't know.