My boat came with a teak platform that was old and small. And a little out dated. When i bought the boat a new platform was a must have.
First make a template to match the back of the boat and cut it out on 3/4 inch fiberglass reinforced plywood.
Make a bottom piece and screw it to the top piece. I used a adhesive between the two so there would be no creeking and such. Used lots screws and countersunk them.
Then you need to fiberglass all the exposed wood and screw and blend it into the fiberglass on the plywood.
Then its time to sand it all smooth and do a little body work with body filler to make it all perfect.
Then the primer.
Then paint and clear. All automotive grade products. And i used agenda traction for the top.
Hand cut and sanded edges to give it a nice finished look.
Bottom finished with a bed liner product.
I also put a 3m clear bra around the front and side egdes to keep the paint from getting scuffed up. But have ni pictures of that step.