1976 Seacraft 23 IB - Rear Deck/Hatch Core Replacement

[aldo]

I used 1" nidacore. The mahogony was a base for my leaning post screws.
I built a frame of 2x6's that would allow for the center of the floor to have a slight crown- (about 1/8") to shed water.
Looks like you have the hard work done. I would just suggest you plan where you will need to screw in your seats or leaning post, and a slight crown will keep you from stepping in water every time it rains. The nidacore will help to shed a lot of weight.
Good luck with your project.