i need a little help with a project of mine.

I have a boat and i have measured the V hull to have a 150 degree angle.
The boat is exactly 8 feet wide, and the distance up one half of the boat, starting from the bottom most V (from out side) to the top of the V in the boat is 31 inches. this leave about a foot on each side of gradual slope outward for the side of the boat.
I am trying to make a cradle to hold the boat on its side.
the question is, how high do i make the angled boards which will support the bottom of the hull not at parallel with the ground and at what angle?
I believe the distance to the ground from the highest part of the hull is 7 inches but doubling that leaving me 5 inches short.
i made a 60 degree wedge at 14 inches .. but that was again way short..

anyone want to play with this with me?

Chris - florida