Jamie O’Brien has always been one of those guys that’s into trying new things. If he’s having fun on it, he’s not scared of using it. And now he’s trying something else out: weird, dimpled fins.
In a sport where image is way too important, he almost single-handedly made riding soft tops acceptable to the masses. Surfing is supposed to be fun, and what someone else is riding shouldn’t concern you in the least. If it does, you’re either a dick or too concerned about your own image. It might be difficult for a surfer with such a high profile to try weird things out–but if you think about it, that’s a bit of a common thread for a lot of the greats. Take Slater, for instance. Although, in the ’90s, it could be said that he was partially responsible for three-quarters of the world’s surfers riding boards that didn’t really work, he’s also been responsible for an enormous amount of progressive designs. Oftentimes, all it takes is one high-profile athlete to open the floodgates. There are a lot of sheep, and only a few shepherds. But back to Jamie O’Brien and his golf ball fins.
J.O.B signed on with 3D Fins, an Australian fin company. Apparently, he’s been riding them for about a year now in a variety of conditions, including his flaming Teahupoo stunt and at the 2016 Volcom Pipe Pro–an event which he placed second in. And yes, it’s hard to say whether the fins actually had much to do with it, because Jamie’s no slouch at Pipe with or without dimpled fins, but Jamie is apparently convinced. Now he’s got a signature fin coming out with 3D Fins.
“2016 Volcom pipe pro was the final test, Jamie decided to ride the new design,” wrote Courtney Potter, the designer and founder of the company. “What nobody realized is Jamie rode the secret fin design during the entire Pipe pro… Jamie decided he wanted the new innovation (yet to be announced) on his signature fin and the deal was done. Jamie O’Brien’s…signature fin will be the most innovative fin ever released.”
So why do they work? Well, here’s how the company explains it:
As we all know, a golf ball with dimples will fly further than a golf ball without. What most of us don’t know is why? There are two main reasons: The dimpled surface reduces drag; The Dimpled Surface improves lift.
There are two types of flow around an object: laminar and turbulent. Laminar flow has less drag, but it is also prone to a phenomenon called “separation.” Once separation of a laminar boundary layer occurs, drag rises dramatically because of eddies that form in the gap. Turbulent flow has more drag initially but also better adhesion, and therefore is less prone to separation. Therefore, if the shape of an object is such that separation occurs easily, it is better to create a turbulent boundary layer in order to increase adhesion and reduce eddies (which means a significant reduction in drag) Dimples on golf balls create a turbulent boundary layer.

Science fact, right? So 3D Fins took those principles and applied them to a surfboard fin. According to the press release, they compared two fins that were identical in dimension, but one had the dimples. They had a guy named Darren Stephens, a fluid dynamics expert, do the testing. Here’s what he found:
A surfboard fin with dimples creates a turbulent flow. Turbulent flow has more adhesion so when you start to turn, the dimpled fin surface delays the flow separation, reducing cavitation (the separation bubble) allowing the foil to maintain performance. When the surfer is turning at high speeds, the turbulent boundary layer helps the flow overcome an adverse pressure gradient and allows the fin to remain attached to the surface longer than it would otherwise. This reduces drag, increases lift and improves overall performance of the fin design.
More science fact!
Jamie O’s not the only one to use the fins, either. They’ve got a pretty solid team already, including Josh Kerr and Christian Fletcher. Chances are good that you’ll be seeing these fins a lot more frequently in the near future.