No concave anywhere. Rounded belly in the nose, flat through the middle (which appeared to your eye as concave) but with tapered or pinched rails, which equates to belly, since it creates what is essentially a convex bottom, to V in the tail. I looked at a lot of pics of stubby hull type boards, and a lot of them are running a deep single fin placed pretty far forward. So I wanted to give that option a go. In addition, there are numerous things I can try with all the fin plugs I have, haha. The board is meant to be surfed in down the line point break surf in so cal.
BTW, here is a pic Bruce Fowler just posted on Facebook, of a board he shaped.
