: Since fiberglass is strong in tension, is it structurally necessary to glass
: the inside of the hull, since this side of the "sandwich" should
: be in compression when the boat is floating?

It has been written before that glass on the inside of a hull gives great strength to the sandwitch. I believe that this is because the inside is in tension while the outside is in compression. This is true everywhere except the cockpit where the paddler's weight on the inside exceeds the water pressure on the outside. Everywhere else, the sandwitch is in tension on the inside.

This is never more true that when an object strikes the outside of the hull. The fiberglass fibers inside the hull absorbs much of the stress.

When I built my Great Auk, I did not glass the inside of the last foot at each end of the boat. All my pinhole leaks came from this area. I will make sure the boat gets glassed inside everywhere this time.

Rick