I made my own
four years ago from closed cell pvc sheet (brand name "Sintra"). It is easy to work with, maintenance free, and shows no UV damage though in the Florida sun this long. I have recently used it to replace the cabin/lazerette bulkhead, as well as replacing the wood core along the gunwale at the hull/deck joint. It won't absorb water, rot, can be fiberglassed in place, painted, and when adhering sections together with a cyanacrylic adhesive such as "Krazy glue" the material will not come apart. I am currently overhauling my boat, and am planning to replace the companionway hatch slides and the wood guides that support the Lexan cabin hatch. It won't replace wood entirely, but I've found it very useful.Mark Major86H23 "Lesismor"