Blisters
Don't fret! Blisters are not that uncommon and quite usual in older boats. Boy, you should have seen my C27 when I hauled her out!!! We're talking THOUSANDS of blisters. If this one only has a few, count yourself lucky.Anyway, to answer your question, blisters usually are caused when the fiberglass is esin-poor. This means that during the layup process, this area received less polyester (or epoxy) resin than normal. This is not usually a structural problem, it just means that if a little water somehow works its way through the gelcoat to the fiberglass, it seeps in a little. This causes a little pimple to form in the gelcoat, which is the "blister".Sometimes, they can even just be surface blisters, where the water has just formed a pimple between the fiberglass & gelcoat. These are even less of a problem.To fix them, if you're interested, you simply grind, dig, drill, etc out the blister, so there is no more water left in it and then let it dry out. Once it is dry, you fill it with epoxy & fiberglass (although the actual fix-method is varied from yard to yard, sailor to sailor), sand it fair & paint over it. Simple yet messy.But James was definitely correct, have any boat you buy surveyed first. Blisters can either bring the cost down or they'll get fixed before the deal is done. Either way, blisters (usually) are more cosmetic than anything. Good luck - C30s are GREAT boats!LaDonna