oops.... I double pic posted! I'm such a virgin to all this web stuff! Where is a 9 year old to do this when ya need one....
Real pic:
Last pic here shows the hull & belly area under the cargo deck. The deck surface is actually removed so we can give it love from above. The deck when attached is water/air tight so you can actually flood the bed and launch watercraft by dropping the tailgate. The area below is about 18" in depth, 52" wide, cross members every 24" or so while having the side frame integrated into the hull corners running the length of the vehicle. Some floatation foam will b added to the outer sides to fill voids and keep out any possible areas for water in case of flood. This will also add rigidity.
Bilge pumps under the deck in all 4 corners, addition bilge above deck, water tight hatches the entire length for service & storage.
In addition for hull strength, under every pumpkin there is a 1/4 thick forged aluminum belly pan. This ties directly into the independent suspension mounting points cantaleivering to the other set of A-arms on opposite side. Since the axles do not move, they bolt into the hull, thus more frame integration.
I never really cross examined the design but every part here really supports the "frame" to create an entire rigid foundation/hull/frame combination!