I must agree with Caleb, mostly. Blisters are just a fact of life with fiberglass boats. Not all boats blister. Boats from all manufacturers blister. It is not a particular problem with Irwins, any more than it is with any other manufacturer. I think that boats in the northern areas, that come out of the water every winter and have a chance to dry out probably blister less than those in the south that stay in the water year round. Don Pascoe has some pretty good information on his site, as do other surveyors. Barrier coats help, according to some, and are probably worth the money to apply. But if you already have the blister problem, it is expensive to fix. The only way to be sure is to pull the boat, and have a look. It is then easy to tell.