I just had my boat in the water for nine days at lake powell. What a great time! I was able to get all the water spots off my hull as I wiped it down almost every day. When I pulled my boat out however my outdrive is covered with white water deposits that I can't get off. The funny thing is it is only the upper unit. The lower unit does not seem to get any deposits at all. I keep a good coat of wax on my outdrive and a weekend at the lake is usually an easy clean up, but this stuff just won't come off. I have tried vinegar, Fantastik, Lime Away got some of it but not all. I don't want to go to rubbing compound if I don't have to. Does anyone have any tricks or superior products that really do the job? I have searched but have not found anything about cleaning the outdrive. Thanks for the help.