: As for stiffness, you cannot detect stiffness difference between a 1/4" strip boat with a aft bulkhead and a 1/8" stip boat with an aft bulkhead. The difference in my deflection tests is less than 1% well below the accepted 3% that individuals can detect, and the same as the 1% variation that is expected from the use of different epoxies.

I avoid using the bulkhead as a structural part of the boat. Have you ever seen a fiberglass kayak with cracks in the gel coat around the bulkhead? This is a result of the skin being flexible and the bulkhead being stiff. The stress riser at the bulkhead causes cracks and eventual failure that would not have happened without the bulkhead. This is part of my reason for my philosophy of working for high skin stiffness. If the skin is too flexible a bulkhead is required to keep the skin from oilcanning. I don't know how thick creates a skin that is "stiff enough" but 1/4" requires no additional internal stiffeners.

• GK