The cabin floor is thickened gel coat, rolled on. I would not repeat that. There are any number of deck or other paints which would work. When I have repaired decks, I used two part Algrip or All craft L P paint with glass beads sprinkled in after the second coat was laid down, and then a 3rd coat covering this. When we rebuilt the cockpit floor in our 2003 C Dory 25, we used thickened gel coat rolled on.
I would probably use Grey Bilge Coat (single part paint) and put
"Dri-Dek" tiles, or one of the vinyl loop carpets, like "DECKadence", or the cheaper pool spaghetti loop mats from American Floor Mat Co. on the floor. Both of these are easy to keep clean, and allow dirt to filter thru--leaving a clean surface on top--and at the end of the trip, the "rug" comes out and hosed off. Any material is vacuumed up. Either of these give a good non skid grip and feel good on the bare feet. Non /skids like "Kiwi Grip" are not so easy on bare feet.
There are other products which are like Dri-Dek, but they are not as soft and flexible--don't contour well, and harder on the feet. I have used the cheaper ones on the bottoms of lockers.
If you want a really course grip--then ground up walnut shells, and sprinkle into wet epoxy, and put a second coat of epoxy over these. I have used this on teak ladders and stairs on larger boats.
You have to be careful with sand. It can be abrasive if you fall or scuff on it. Also any sand has to be fresh water washed and well dried.
