Black Project fins asked me what goes into choosing a fin?
The smallest fin you get away with will be the fastest.
Some sailors swap and change all the time, I know within the first broad reach if a fin is going to work or not.
To get the fastest fin you have to consider, sail size, water state, board size, angle to wind your runs will be.
Asymmetric fins are the fastest but only one way.
The broader the course the more rake you want on the fins leading edge, the tighter the course you want a more upright fin.
In luderitz we are sailing on a man made canal 4m wide and about as flat as you can get, I’ll be using my Patrik Diethelm 41cm board with a 16 – 18 cm asymmetric fin. Type X or XLS. Sail size 5.4 to 6.4
In somewhere like Port St Louis the course is very tight, I would use a more upright slalom fin on a larger board Patrik Diethelm 49cm or 53cm with Type R 26-28cm. Sail size 5.4 to 7m
In Fuerteventura I would use a more swept fin like the Type S 26.5 on Patrik Diethelm 43cm or 49 board. Sail size 5.4 to 7m
In Karpathos I would use either Type R or RS 26-30 cm on a Patrik Diethelm 53cm board
The bigger the board the more fin choice there is, on a 110 ltr slalom board I could use 32 – 78 cm fins Type R, RS or S.
The smaller the board the more perfect the conditions have to be.
Horses for courses.