what fin size for a 6.8m on a S type104

[Paulc]

Hi Dolf,
i am a recreational sailor that is at a skill level of planing out of some of my gybes. I just want you to know that your formula (as simple as it is) works perfectly for me and my boards. i am 84kg and use trueames fins and starboard boards. when i apply your formula to come up with the smallest area fin that is usabe and then take the next size up it seems to be right on. i applied your formula for my stype 126and 104and kombat 106 (used in freeride mode).

regards