Raw Water in Engine
I used Interprotect 2000 23 years ago. Didnt have too many blisters but some on C&C 32 1984. I carved all I could see after stripping 10 years of bottom paint off with paint stripper formulated for fiberglass. Put on 3 coats of interprotect and then VC 17. Boat is in freshwater so I only reapply bottom paint where needed. If you race I would suggest four coats of interprotect and then sand smooth as interprotect is not very smooth.