Our bamboo core center fins fit standard US fin boxes.
A shallower fin works well in flat water. The better your forward stroke is, the smaller the fin you can use with the added benefit of less drag.
For a single fin setup, in the surf, you generally want 1″ of fin height for each foot of board length. You would reduce the length if you use side bites in a 3 or 5 fin setup.
6″ – 22 square inches, 5″ base
7 3/4″ – 28 square inches, 4 3/4″ base
8 3/4″ – 37 square inches, 6 1/2″ base