I'm afraid a bottom scrubber in a marina would concentrate antifoul paint
polutants in the water under this operation..

I know this was a problem with scrubbing navy ship bottoms in the shipyard I
worked in in San Diego. The EPA or some 'guys' came around regularly and
took bottom sediment samples and collected shell fish samples. We had to
stop the practice.

At the marina I'm in now there are rich shell fish beds under and near by.
They don't allow any divers to scrub bottoms there for that reason.

Steve
s/v Good Intentions