BTW, the slot on the fin I was using is only about 2cm long in a 25cm fin, not one of those 'double' fins that I remember seeing in the early 90's. In choppy conditions, (such as 25knts on Botany Bay) is it really possible to eliminate spinout with technique, set-up, etc?
I'm happy for you to say "yes", but if you do, could you also tell me how to do it.