David, I'm not sure where carlins are involved in the yare, but with a flat rear deck there needs to be some kind of support....houses with flat roofs and 10ft of snow have to be built differently than steep A fram houses.

But if the deck is low and you want an unobtrusive front deck beam you could use 2"unidirectional carbon fiber tape on either side of 3 layers of 3mm plywood, regular glass would work too. as far as flat rear decks are concerned I built a North bay and instead of carlins I glassed under the deck panel before installing and glued a 1/4" x1/2" strip of mahogony (any strong resilient wood ) then glassed over that with a bias strip of grlass 3" wide. I think if you were going for simplicity make the boat without bulkheads,and simply glass the rear deck underside,make a minicell foam pillar about 2ft long glued or wedged behind the back beam extending down the center of the kayak supporting the deck.

I had a kevlar necky swallow without bulkheads that I was concerned about sitting on the back deck and this worked well.

re.the loser issue , I think one has to lose a lot before earning the title.