This series of photos shows how I resolved my issue with the diagonals, after Jim's helpful comment and my new understanding. I made a triangular piece of wood that fits on top of the keel-stem that sits immediately on top of these piece and goes from Bulkhead #6 to the land point of the diagonals. This piece has been epoxied in and filleted today. I will first glass over it with 12 oz biaxial e-glass and then fit the diagonals.

The amazing thing about the tetrahedron issue is why I couldn't see it. A couple of months ago I had been considering moving to one of the Gulf Islands, for the building of this boat, and living in what is called a Yome. I had looked into yurts but the smell of the covering fabric drove me nuts!

Red Sky Shelters make a structure that uses silicone impregnated canvas. The samples where easy on my nose but in the end I couldn't coordinate the move. It would have been good. I had a great building cover lined up with a view of a saltwater inlet and the occasional bald eagle flying by.