The problem I had with cut away fins, were that they never drive and the would always side slip. To ensure that my Offspring wouldn't do that I created a fin that had added base and a considerable amount of rake. You now get the looseness of a cut away and the drive for your maneuvers and the stability to nose ride.
Aloha Kanoa D.
Kanoa Size Chart:
7.25" - 2 plus 1 Long Board 9'6" or less/mini tank
8.25" - 2 plus 1 Long Board 9'4" and up
9.5" - Single Fin Long Board 9'2" and up