Buy a Sheet of the Better plastic Foam Cores,You will do yourself a favor every time you open it the (light weight)

does anyone here understand what happens to wood in the marine environment? DO NOT USE WOOD if possible. Wood does rot and that is WHY certain manufacturers DO NOT use wood, they use a urathane foam core.

Thanks Guys! Foam Core is another option, afterall we are only talking about hatches here. Wood will only rot if it is exposed to the environment. As long as it is kept sealed, it should not rot. Either material will work. Foam, more $$$.