Vintage Seacraft 21' -- 1963

[3rdday]

I believe 8' midship and less at the transom!
It would make sense since Moesly was first a pilot, he was very clever in his designs, he probably applied aviation principals. Most airfoils are thicker in the front and narrower in the back.
Sailboat hull same way. As water/ air moves around the thicker mass once it reaches the thinner mass it almost pushes the airfoil or hull forward. The water has been displaced or separated and wants to "come back together" so it helps to move the object forward.