hmmmm.. before I did repairs I had leaks but I never had any problems with the hulls being particularly heavy. Then I sealed the hulls up completely, so there should be no leak points, and certainly no new ones if anything there may be some spots I missed around the seam at the top. Anyway, after the repairs I had about 8 hours of sailing time with no problems and then the next time I went sailing I noticed the difference after I was done and in the process of pulling the boat back up to the boatyard. Could this happen this fast?