I got this really cool rook pattern carbon fiber on closeout and wanted to use it somewhere. I figured the floor of the cockpit would be a good place. It's an area of the boat that needs to be tough and a location that I can show it off without taking too much away from beautiful wood grain of the plywood. I put down the carbon fiber and a layer of 4 oz glass over the top.
The green tape is locating the inside location of those gunwale tank bulkheads. The next step was gluing in those bulkheads.
After they were sufficiently staked in, a fillet of epoxy filler and glass tape was added on both sides to further strengthen the bulkhead junction to the hull.
Next up, splines were added between bulkheads for supporting the tank skins.
The trickiest pieces to define were the vertical walls of the tank. I made templates from construction paper for each side along with the foredeck top. My buddy Nori helped out as much as she could.
After shaving down each side to a tight fit, I glued and clamped them in.
I decided that the tanks didn't need to extend all the way to the transom so I tapered them to a point just forward of where the traveler will attach. The picture below shows the boat after those faceted pieces were attached to the back of the gunwale tanks. 
Next I added the splines between bulkheads to define the top of the tanks. It is starting to take shape!
