Most interesting. Intuitivly, when I first started making thick foild fins, in 1960, I started at about a 10% ratio, and quickly increased up to around 12% to 12.5%, based on board speed and turning ease. What you’ve come across, is very validating. Almost equally interesting, are what I call ‘‘the flat earthers’’ who don’t believe that there is any merit in thicker fins. Surfboard folks should always bear in mind, that surfboards move over the water, while a surfboard’s fins move through the water. Thanks for that little gem.
