I'm putting a "fuel cell" aluminum fuel tank in the bow compartment of my GV-13. Last night I started dry-fitting and blocking the compartment. Everything is just hot-glued at this point to stay together, so it's easy to change right now. My idea is to have 1/4" walls on the sides of the tank, and a deck above with a waterproof (purchased) hatch to gain access to the fuel fill and storage compartments port and starboard. I'll also utilize the opening on the top of the tank to vent to a deck fitting:
It's not sealed. There's a hole cut in the fuel platform for the fuel ports, open to the limber hole in the bulkhead. The fuel line will be routed to starboard under the platform, and the fuel tank itself will be through-bolted with rubber pads:
The sides of the platform are open to the storage compartments (I doubt I'd be able to get it fully air tight):
