Does the word blisters strike terror in the minds of all sailors? Are blisters in fiberglass gelcoat strike us as a cancer? Are there different types of blisters? Are some considered "cosmetic"? I have seen some worse case sinerios where the blisters are quite large (4-6 inches in diameter) and deep enough to penetrate through the hull. I’ve seen others that were the size of a dime and appeared to be skin deep. How quickly will the little ones turn into big ones? Does it depend on what year the boat was made and thus the type of resins used? Anyone care to expound on the problem of osmosis? Would you buy a boat with small blisters?