[KeepitReal]

Can anybody identify what is going on with the part of my lower unit turning white? Is this galvanic corrosion? If so, I'm sure I can do some forum searching to find out how to fix it but if anybody has any secret tips, they would be greatly appreciated

[Dredd]

It just looks like mineral deposits to me. When the drive is hot from running, the water dries on it fast and leaves deposits.
I've read that muratic acid will clean it right up. Just follow it with a coat of wax.
A drive shower will typically keep the drive cool enough to alleviate the problem.