I bought me a Starboard Rio M to teach my children how to surf. It standard comes with a Shallow 310 FRN fin. I would like to buy another fin for more performance. In your tuningtips you recomment a Drake R13 Race NR 540. Since my largest sail is a NP V8 8.1 m2, I think a 54 cm fin will be to big.
I could use your advise to get me the right fin!