I found the same thing accidentally (and repaired it) when I replaced my fuel tank. This partially has to do with the way the hulls/stringers were laid up and 40+ years of freezing and thawing cycles (some without a tarp/cover). I hope you don't have the same problem, but I'd be willing to bet this is the issue. It's easier to repair from the inside
even if you sawsall through the hull like I did. I have 130+ hours on the boat now after the repair (in some real nasty conditions) and the repair is holding up great.
http://www.classicseacraft.com/commu...t=28644&page=5
