Joe wrote:
Actually Doug i think it's copper leeching in the osmosis blister from
the bottom paint...thats just a guess. Ive seen it on many fiberglass
boats


OK, that sort of makes sense if the boat has a really copper-heavy
bottom paint and rather porous gelcoat. I've never seen anything like
this but apparently you've seen a lot more blistered boats than I have
(easily possible, since I haven't gone looking for them).

DSK