[RidgeRunner]

If you want to get fancy with it make a mold to the exact outside demensions you want. Molds can be made from plywood laminated with formica use modeling putty for the radius and bend the formica for the radius corners . Glass the shell, add the core and glass the core gelcoat before or after for a factory like hatch. Lots of work and $$$ is the downside. Otherwise you laminate your precut plywood, leaving the plywood a bit smaller than your desired finished size (say 1/2" smaller than your opening)and work to it with glass and grinding. The top side radius and the corners of the lid will take the most time. You will not be able to make a tight radius with 1208 or any other multi-layer fabric IMO. You will need to do it with multiple layers of matt and hardware cloth. A 1/4" or less roundover bit on a router for the top edge all the way around would look nice and can be glassed without cutting into strips. You have to be creative on the corners sometimes. Wellcraft used a chopper gun on the liner and hatches, matt is close to the same when finished. Multi-layer fabric is great for the top and bottom. Be mindful of the thickness at the edge, Wellcraft did not run the core all the way to the edge on my boat. Measure the distance from the deck to the lip where the hatch will rest. It is probably only 3/4", meaning by the time you glass your 3/4" plywood on both sides your installed height will be higher than the rest of your deck. After you get the glassing done is no time to discover you have to grind it down to make it fit. BTW - NOT A GOD, bilge boy maybe. If you go for it post up some pictures.