I dunno That sure hasn’t been my experience with half a dozen 20 or more years old hollow hull boats over the decades and four of them Sunfish. A thorough leak fix in the beginning and I get five or six years between new seeps. Even then I know why since they are usually the result of me grounding the dagger board or other abuse. If you beach carefully and don’t have kids jumping on the deck while it’s parked in the yard and don’t bounce it down rocky paths on a suppository dolly and don’t just do quickie bubble gum wad in the hole putty patch jobs IMHO the hull should stay solid and dry for many years.From my experience (I sail a '74 hull), the older hulls have a number of leaks, so that you could spend all your time repairing your hull,
The slot isn't a cosmetic area and doesn't always get lots of gel coat. Visible fiberglass isn't always a sign of a leak. You have to leak test to be sure. Don't just guess.Looking in the dagger board sleeve I can see the criss cross pattern of the fiberglass fabric. Will this cause the boat to leak or is this still waterproof? How do I fix it if it is a problem? I read somewhere to line the front and rear of the sleeve with green grass carpet. Anyone heard this?