Great information guys thanks a lot.

I am using bass wood for the central part of the deck as you can see in the earlier posted pics and the strips are just shy of 1/4". This seems really stiff even without glass and with my forms being placed at 12" centers.

A layer of glass on the inside of the deck might be a good way to increase the stiffness between forms or carbon fiber?

It sounds like the stiffness of the deck is the most problematic issue for us kayak builders moving into SUP's. Of Course rails are talked about quite a bit as well.
Im using cedar strips for my rails and will be stripping a slight radius into the deck by hand beveling two strips to make the corner and beveling about 4-6 to get around the soft chin and Hull.

Should blend quite well without showing any endgrain.

Will post more pics tonight after the deck is done.

Robert, Visionary