I was at Marks shop in the fall of 06' and he was repairing yet another gel-coat problem. I guess there we're air pockets between the gel-coat and fiberglass and they just keep popping up.
Bingo! That is exactly the problem I was referring to when I said that their lamination is sub par. Blisters are a tell that the hull is having problems. I know exactly why the blisters happen. I have seen the reason this happens, with my own two eyes. If he is only getting blisters, he should consider himself lucky! Let me guess, if he pushes the blister in, it will go in somewhere around 1/8" into a cavity? The reason why it happens is because they use/used a technique that is frowned upon in the industry. They do it because it makes lamination much faster and easier, but it is also very risky. If those air pockets are between the glass, which they usually are, the glass does not bond to the next layer. This can be dangerous! Since they are not laminated together, the laminates can pull apart and cause disasterous effects!!! The hull could delaminate because of this problem.