SeaCraft 20 '74 hull, post soda, now I...

[flyingfrizzle]

I agree with Islandtrader on this one, There may be some blisters but yours looks like air bubbles in the lay up when they glassed the hull in the mold. The gel hides most of that stuff if they don't roll the air bubbles out well but they will show up one day. The give away is the amount of them in the step area. That area is prone to getting air in it when laying up due to the curves. They appear uniform down that step area. Most blisters bubble outward cause the moisture swells the fibers and will be spongy. They may of made it easier for water to get into the fibers so check it well but you may be lucky and not have much damage. I would check down the notched areas on each step. You probably will find the most of them in those areas. Epiglass epoxy resin is good stuff be man it is expensive. Any epoxy based product will work well. I use the interlux watertight epoxy filler and have good luck with it doing what you are trying to do. It is thinner than most fillers and goes in the small spots well, almost like a glaze. It will fill easier and hold better if you tapper and feather the holes out some before applying.