Ok, instead of being a wise guy, I'll try to help.
First thing that comes to mind is cellular PVC sheets. It comes in 1", 3/4", 5/8", 1/2" or 3/8" thickness. The sheets come 4' wide by 10',12'18',20', and of course 8'. The longer lenghs should make it an almost seamless application. The product cuts and routes like wood, with your standard wood working tools. It is completely impervious to fresh water as well as salt water. It natural color is white and there is even a wood grain texture if you like.
View the following link for certainteed and you can cross shop other manufatures like Azek and Versatex
http://www.certainteed.com/products/trim/sheets
Hope this helps, and now I going to go smoke some
ahhhh just kidding