mgarvie wrote:
Won't that really mess up the bottom of a fiberglass boat? Not that it's in
the best shape after all the
coconuts and lawn chairs I've hit. Wouldn't there be
some kind of acid based product that will remove them?

Scrape off what you can , then try muraitic acid. Sno-bowl toilet
cleaner might work also. Rubber gloves are essential, don't breathe the
fumes. Sam