Blisters arent a terribly big problem and many of the previous posters have good suggestions on how to fix them. But most
blisters are cosmetic, the real problem is hydrolysis. Drying out the
boat and patching the blisters will just make the blisters go away. Because you cant dry out the
boat completely there is still
water inside the laminate. Over time the
water will weaken the laminate and form new blisters again letting more water into the laminate and then the whole cycle just repeats.
The only way to really get the water out of the laminate is to recognize the unfortunate fact that the already osmotic laminate cant be save. The only solution that has a real shot of preventing blisters for the rest of the life of the boat is to remove the affected laminate, have new laminate put on using top grade gel and barrier coatings, and constant vigilance