"It looks an awful lot like there is an unintended bump in the foil about 2/3rds of the way back....that was my point. The glass layer lines give it away. "not sure who shaped them but I inspected them very closely out of the box and they look great. I think the “bump” you might be looking at is actually concave as the inside foil is concaved - one of the shots shows this lined up with a bit of wood to try and show this off a bit…
the only fault I could pic is that the leading edge is foiled about .5mm out on the LHS fin which I cant imagine would matter at all on a surfboard fin.
the first 1/3rd and last 1/6th are convex…half the fin in between at the base is concave…that’s what I saw, and it looks to me like it is asking a lot of the water flow…especially with the curvature into the concave…
I haven’t done a lot of concave foils though, maybe it rides great, but I’m sure I would have carried the concave all the way to the trailing edge and made the curvature greater at the leading edge of the concave than at the rear portion.