You need to find out WHY YOUR BOAT SANK. The picture below is an original 1969 20sf, You can see the water line. It sat in a slip for 2 years neglected without a bilge pump installed. The slip backed up to a main entry to the harbor with boat traffic busting wakes on it's transom every day.
The inherent forces applied by mother nature are to sink a boat. All boats that float on water are collectively fighting these forces ALL THE TIME. In other words your boat is always sinking and we are constantly trying to keep our boats a float. For your boat to sink something had to fail and you need to find out what it was. The engineering and design of the seacraft was years ahead of it's time and provided your boat was in good working order (thru proper maintenance)it may not have been the boats fault.
strick