Look, I may be way off here, but I got some excellent responses to my question regarding leaking chain plate penetrations. First of all, these blisters represent a potential weakness of fiberglass hulls and have to do with the water reacting within the matrix, and may be unrelated to hull penetrations The West System "Fiberglass Boat Repair and Maintenance" manual tells how this is dealt with; along with other, similar repairs. Another excellent suggestion I got was to examine the suspected problem in detail before jumping to conclusions regarding the extent of damage and what the root cause is. As a minimum, looks like a haul-out and second opinion are in order. Best of luck!