"Most cases of hull blisters t
"Most cases of hull blisters that I've seen are in the underlying hull, not in the gel coat.
Sometimes, there are just a few...sometimes it looks as if the hull has a bad case of acne.
The fix is to grind out the blister and fill it with the correct epoxy, and then apply a barrier coat (not gel coat).
I've seen boats in the marina that have more than a blister per square foot and when the yard finished grinding and filling, they barrier coated and then bottom painted (two coats) the whole hull.
If its just a few blisters, then it's possible to do it yourself...more than that, its a job for a yard that knows how to do it correctly. Not a job for an autobody shop.
Blisters on boat hulls usually have trapped liquid in them, not something the average "vette" specialist ever sees. Gel coat only "dings" are usually DIY jobs."