1970 Sunfish on eBay

The problem with those old sunfishes is that the EPS foam floatation inside the hull slowly absorbs water vapor over the years, the water vapor condenses inside the closed cells of the foam and the boats can take on a 100 lbs or more of dead weight. The cure is to cut holes in the deck to dry out the interior, but the process can take months and is best done over the winter.