Stitching the 2 (curved) panels together then folding them open imparts the designed 3D curves into the hull bottom. At this point they are simply resting on the bulkheads (they would adopt a similar shape if opened the opposite way - upward - even without the bulkheads). I'll next stitch hull side panels to these bottom panels. Again, curves cut into the bottom and side panels will impart 3D curves once stitched. At that point, they'll begin to be glued (epoxied) together. Once cured, stitches will be removed and additional epoxy and ultimately glass applied for strength. There will be no nails or pins or screws in the hull or bulkheads, just wood, epoxy, and glass.