What about drain holes thru the stringers and transom knees where they join the transom? The center of your boat looks to be well drained; but can't tell if the open areas outside the stringers have adequate drainage.
Hick
I forgot to show the picture of the drain holes in the stringers, good catch. I didn't knotch the knees instead I cut holes just in front of them. The water if any should drain in the bilge area, which is the gas tank area. Here they are.