Unless you are a cabinet maker, don't waste your time. You can buy a 10' section of black, lined sewer pipe and order caps for the end. Mount them with stainless steel clamps and drill four inch vents in both ends for ventilation. It will last forever and will keep everything nice and dry. On my hobie 16 I used a 12" pipe. On my Hobie 18 I used a 15" pipe. Do a search because you'll find loads of instructions on this website.

I think the last one I made cost me $110 for all the materials.

Wyatt