This forms the aft casting deck so the hatch lids will be reinforced. A small hole against the transom will allow the fuel hose to come up through the rear deck and attach to the outboard. 3mm plate forms the hatch lids which is level with the aft thwart seat and a sopac style hatch forms the livebait tank lid. All this area will be carpeted.
A small stern deck of 1/8" ply wouldn't add much weight and allow you to lower it into the water by it's bow line, off a boat or dock without taking any water on board. This is the first attempt, but I'm sure it wont be the last.