What fin for 6’8 single fin

I think the ‘forward’ reference is that the wide point is more like 15% from the front rather than 30%.

Yes :slight_smile:

From that to the trailing edge is close to flat 

The  face of the fin which is under pressure becomes a planing surface with the template controlling the effcts of that surface , similar to a towed in single foil.

The fin now becomes a planing surface rather than just a rudder . - more Fun !