Surf Science: Off Balance

Asymmetrical surfboards: obscure design or a legit new fad?

By Cyrus Sutton


The first asymmetrical surfboard tails were birthed in the mid '60s when legendary San Diego shaper Carl Ekstrom was looking for a way to get his clunky longboard to perform equally well frontside and backside. After patenting the design a few years later, the quirky tail shape was largely forgotten until surfer Richard Kenvin collaborated with Ekstrom to pull the design out of obscurity.  Together they've designed a wide, three-finned board with a keel-shaped fin on the inside rail and a two fins on the outside rail reminiscent of a quad. "Carl's boards are really functional because all the drive is in the toeside, allowing the board to have a pivot point, like a thruster," says Kenvin. "But there is no trailing fin dragging and this allows for more planing surface, so the board is fast and skatey. The heelside has a shorter rail line with more curve and a pair of fins, the combination of these elements is more conducive to tight arcing turns."

Today, 22-year-old surfer/shaper Ryan Burch has taken these theories to his own boards. While Ekstrom and Kenvin's designs look like the love child of a fish and an egg, Burch's designs are lightly glassed, thinly foiled shred sticks resembling the modern thrusters he grew up surfing.  After surfing and talking design with Ekstrom and Kenvin, Burch thinks asymmetrical boards have the potential to be the ultimate high-performance surfboard. "Now whenever I ride a thruster, I'm always amazed at how much work it is to just keep them moving down the line," says Burch. "But when I jump on one of my asymmetrical shapes, it feels effortless. I'm no longer thinking about pumping all of the time to keep up my speed, now I can just focus on where I want to go on the wave."

At first glance these boards look a bit funky and off balance, but when you think about the relationship of your ankle to the anatomy of your feet it starts to make sense. The calves, arches, and toes all contain muscles that give you control on your toeside that simply don't exist on your backhand. These boards feature subtle design tweaks with concaves, fin tow angles, and configurations that take these differences into account and allow the rider to potentially achieve a more effortless ride without sacrificing control in many situations.

Despite the renewed buzz, including Kelly Slater riding some asym tails recently, critics cite the key role a center back fin plays in maintaining stability during more critical and inverted maneuvers. That said, the development of the asymmetrical board is still in its infancy and testing has been limited to a few surfers in limited conditions. Open-minded individuals like Ryan, Richard, and Carl will no doubt be leading the charge on this front for years to come; and who knows, adequate R&D breakthroughs may occur that could render the thruster as just another "retro" surfboard.

For more about Richard Kenvin's surfboard explorations, check out