Surf Science: Faster Fins
Dimples changed golf balls, and they just might do the same for fins.
As seen in the May 2013 issue of TransWorld SURF magazine. Subscribe today and get a free gift!
Fins are the least understood—and perhaps most overlooked—aspect to the performance of a surfboard. The main modern advancements have been the ability to remove them and different attachment designs along with lots of subtle design and material tweaks. However, a new fin company has borrowed an innovation from the golf world that might just be the next step forward, thanks to a mad scientist in West Oz and pro surfer test pilot Josh Kerr.
3DFINS is based out of Western Australia, and, of all things, their story connects back to the unintended improvement of golf balls. Before 1905, golf balls were smooth. Then a funny thing happened: players started noticing that older, beat-up balls would sail farther on a drive than new ones. Eventually they discovered that the pits and divots in the older balls allowed them to fly through the air with less resistance, thus traveling faster and farther. Many than 100 years later, 3DFINS has applied the same aerodynamics to surfboard fins.
"I was playing golf with a mate, and we were talking about this ball that corrects the flight of your drive," 3DFINS designer Courtney Potter says of how the idea came about. "The next day I was checking the ball's website and aerodynamic info and had a golf ball in one hand, a fin in the other, and had this vision of fins covered in golf ball dimples and how insane it would be."
But how do golf balls flying through the air correlate to a fin in the water? "There's not much difference between air and water—both are considered fluids, water is just thicker and slower moving," Potter says. Something called "turbulation" causes the fins to slice through water faster than those without dimples. "The dimples create small vortices that suck the flow to the foil [like a golf ball]. This reduces flow separation from the foil when turning, so instead of blasting through the water, its cuts and slices through," the mad scientist says.
And while all this technical talk is great, the proof is in the pudding. Josh Kerr has proven to be an awesome test pilot. A master of all conditions and surf craft, Josh logged the best result of his pro career when he rode his signature fin during the 2012 Pipe Masters. A win over Kelly Slater and runner-up finish proved that there was something to the dimpled fins. "You just get that extra bit of squirt," Kerr says. "When they first approached me, I was like, 'What? This is gonna work!' As far as the design and stuff, I just told them it had to be fun," he adds. Kerrzy isn't the only one singing praises for 3DFINS: "I gave a pair to Kalani David, and he's been ripping on them," Kerr says. "All of the feedback has been really positive."—Justin Coté
Above: Josh Kerr on 3D Fins.