Low aspect ratio spitfire cutaway box fin, completed.

Custom Roy Stewart hand made wooden longboard fin with fibreglass base for a standard singlefin box.

The fin shown is a 10.5" low aspect ratio spitfire cutaway fin, other templates include D fins, Hatchet fins, pivot fins or any custom shape of your own.

The elliptical spitfire' fin has the lowest induced drag of any planar fin shape. This means more drive, more power, better control, and greater speed.

http://olosurfer-woodensurfboardsatpipeline.blogspot.com/2010/12/low-aspect-ratio-spitfire-cutaway-box.html

Elliptical wing explanation on wikipedia:

http://en.wikipedia.org/wiki/Elliptical_wing