Epoxy filler not fiberglass
Many boats last a long time with plenty of blisters especially if you are planning to dry-sail and not store the boat in the water. I would still probably opt to fix them. It is not that difficult, just time-consuming.There is a lot of good information about blister repair on the web. The holes should be filled with an epoxy filler not to be confused with epoxy resin. It goes on like bondo (or wood putty). You have to sand well, make certain that there is no residual moisture in the area, over-fill with the epoxy filler, fair it down with wet sanding, then apply gelcoat over the patched areas with a sprayer. The last step is to sand down the stiple (texture) of the gelcoat that you have applied with wet sanding finishing with 400 grit paper.If you were planning on keeping the boat in the water, I would suggest that you then do a good epoxy paint barrier coat and then bottom paint.I know the gelcoat is not usually applied with a sprayer, but a professional plastic mechanic that has done work on my new boat when it was delivered taught me that trick. It worked great. He buys disposable propane cartridges to power a small sprayer with a glass bottle. You can find these in most paint stores.