Thanks for the feedback. Phatphil I would be too nervous to use HCl on an aluminum boat. I worked 30+ years for a company that makes HCl so know a lot about it. It's hard to make it stronger than about 38% and it will flat out dissolve aluminum. Drop a piece of aluminum it 30% HCl and it will fizz like Alka-Seltzer and gives off hydrogen gas. If you dilute it to 25% or less it won't fume but is still pretty potent. Any little imperfections in the paint may let the acid contact the bare aluminum and probably pit it so be careful.

I think if I go the dock route I'd probably have to pull it after a week and see what I got. I've had it in the water a week at a time but always cleaner water like the St. Clair river or a clear lake. Never had anything on the hull after that but Erie is a lot different. My old boat had a lot of white on it and in lakes with tannin stained water it would stain the white areas after a week but it would wash off after a while once I was in different water or washed it.