Painting
After your desired finishing, the insides need painting. Your choice, paint, gel coat, epoxy etc. I used 3 coats oil based porch and deck enamel because I had 4 gallons on hand.
If you zoom out, you will see two holes in front of the center seat from the floor into the runners. These are to drain any water into the runners and get pumped out at the back of the boat.
With the boats flipped over finish the outsides. The white one is pretty smooth and will only require a little sanding and couple coats of gel coat or what ever you want.
The other one is a little rougher. It can be ground, sanded and filled to your desired smoothness then gelcoated or ?
Since the rough one will be used on the beach in Alaska I chose not to be too concerned how smooth it was. Ground a little and gelcoated with 3 coats gel coat.
Both complete, you can see the difference in smoothness on the sterns.