The floors are resting on 1 x 1 x 1/8" angle aluminum angle riveted into the faces of the benches. The individual boards are screwed to two 1"x 2" strip running across the underside of each floor sections. The Cypress boards are each about 30" long between the benches. I thought I might need a center brace running down to the floor, but the boards have almost zero deflection with my full weight on them, and I run about 240. The floor sections are not fastened into the boat an any fashion at present, as I wanted them removable for storing out of the elements when the boat is not in use. I am investigating some sort of latching mechanism to lock them down while underway, trailering, or (God forbid!) it ever gets swamped. Maybe something as simple as stainless barrel bolts, or something similar, stationed at each corner.