“The hydrofoil has been solving all my problems lately,” says Kai Lenny over the phone in an exuberant tone.

The young watersports prodigy from Maui set the surf world on fire when he released footage of him prone paddling a shortboard into a wave off of Namotu Island with a new kind of hydrofoil strapped to its base. While this isn’t the first wave to be ridden on a foilboard, the significance lies in the concept of the infinite surf loop. In the video, Kai kicks out of the back of the first wave and pumps his board to find some magical force that keeps him floating above the water, all before circling back to the wave behind and button-hooking into another left. Kai has introduced the concept of the continuous ride to free-form surfing. Never mind that this theory is one kitesurfers have been exploiting for years, the subtle but equally important universal reveal in Kai’s handiwork is that his new foil transforms just about any lump of energy moving through the ocean into a perpetual source of bliss — the feeling we get from gliding down a face.

Nine-year-old Kai Lenny learning how to foilboard, boots and all, during the Laird days. Ironically enough, the first time Kai dropped in at Jaws was on a foilboard. // Photo Tony Harrington

Nine-year-old Kai Lenny learning how to foilboard, boots and all, during the Laird days. Ironically enough, the first time Kai dropped in at Jaws was on a foilboard. // Photo Tony Harrington

Kai Lenny didn’t invent the surf hydrofoil, but at the age of nine, he was in Maui under the watchful eyes of Laird Hamilton, Rush Randle and Dave Kalama when air chairs were being strapped to surfboards and towed into Jaws via jet skis. The foils of those days were hulking machined blocks of weighty aluminum that required snowboard boots to cement an awkward and anything but fluid connection between man and monolith contraption. With that mediocre state of technology, foil surfing didn’t amount to much more than mere spectacle and a niche activity enjoyed by a few of the Maui tow crowd.

While foils never gained widespread adoption among surfers, the foil secured a small foothold in kiteboarding with characters like Mango Carafino. However, the struggle to deliver new construction methods and user-friendly foils that freed kiters from the awkward tug-of-war between kite and moonboots continued. A few kiteboarders plunged into foiling headfirst, but the real advances in construction and design came only after kite racing adopted the foil — the most efficient way to go fast in straight lines around fixed courses. As racing tends to do, the narrow pursuit of speed finally attracted the diversity of talent to challenge the durability, weight and performance barriers plaguing the early hydrofoil. Custom foil foundries popped up in backyard shacks and garages around the world as demand for these aquatic hoverboards finally took off. Fast forward three years and almost every major kite brand has a freeride foil, none of which seem to stay on kite shop shelves for long. Despite this progress, one giant problem still remained — with an evolution focused on speed, everyone ignored the lesson Laird taught us: foils were meant to be surfed.

Kai shoulder hopping a friend’s wave while illustrating a hydrofoil’s preference for a completely different domain than a shortboard. // Photo Tom Servais

Kai shoulder hopping a friend’s wave while illustrating a hydrofoil’s preference
for a completely different domain than a shortboard. // Photo Tom Servais

When a 23-year-old tells you there’s a problem in the world and that he intends to solve it, this really makes you stop and think. As a professional athlete, Kai struggles with a performance gap despite a strict regimen of perpetual forward movement. Weight train, paddle session, replenish nutrients, rinse and repeat. The biggest challenge to Kai’s hectic schedule isn’t endurance, motivation or focus, but rather it’s the lack of conditions. According to Kai, “The first problem I wanted to solve was how to make a foil for conditions I can’t surf at high performance levels.” While most of the world’s surfers are cursed with below average waves, apparently this is also a problem shared by jet-setting super athletes. If it’s not windy or the waves are small, Kai struggles to ply high-level surfing on little more than mush.

Experimenting with foils latched to the bottom of a SUP, Kai first changed the game for SUP downwind, a sport he euphemistically describes as the least exciting of training activities. Essentially, the problem was not the conditions, but in Kai’s tools until he began working with Alex Aguera to build a foil that would turn a 14-footer into an agile surfing machine. Tweaks with a lower aspect front wing and dialing in the back wing resulted in a Youtube video (uploaded last April) that positively proved the concept of downwind SUP hydrofoiling.

Kai’s proof of concept for the infinite ride started by speeding up tedious SUP downwinders with a hydrofoil. // Photo Tom Servas

Kai’s proof of concept for the infinite ride started by speeding up tedious SUP
downwinders with a hydrofoil. // Photo Tom Servas

A couple of months later when Kai released the Namotu footage of prone paddling a hydrofoil into the established dominion of a surfable wave . . . the Internet exploded. Scrolling down the list of Youtube comments, there are a few jabs of typical narrow-minded surf bigotry flavor. Reactionary fear and loathing for anything new and different is the standard passé of internet-surfing trolls harping under the pretense of water safety.

Kai himself was expecting a lot more negative feedback, but he says the response has been overwhelmingly positive. Kai tells me it’s common sense.

“No one likes paddling, no matter what they say. If I can paddle once and catch three back-to-back waves then I’m doing more of what I love to do, which is riding waves.”

Working with Aguera, Kai’s main goal with the foil was to feel like there was a rail under the water. Instead of flat pivot style turns, Kai lays giant carves to get the same feel and drive a surfer squeezes out of a performance surfboard rail. A lot of the world knows Kai Lenny is a class of highly mutant athlete, and while foiling back-to-back waves ultimately took hours of practice and testing, it’s not outside the bounds of the above average surfer. Starting with the usual experimentations of foot placement, the original order of takeoff involved standing up before the foil lifted, but with practice, Kai actually chest paddles until the foil is planing, and from the air, springs into position. The evolution has only just begun.

When it comes to the technology, Kai likes to draw the comparison between freeride and wave riding kites. “At first everyone wanted fast turning kites in the surf, but when you’re strapless waveriding, you want slower kites with more constant power and it’s the same thing with hydrofoils. I don’t want something that reacts super quick. I want something forgiving that I can push to its limits.” This is the analogy that makes sense of all the early attempts at riding waves with a kite, and explains how the wrong foil in the surf will push even the best athletes beyond their limits.

Kai demonstrating the little-known truth that foilboards have an underwater rail that drives harder than any conventional thruster. // Photo Tom Servais

Kai demonstrating the little-known truth that foilboards have an underwater rail that drives harder
than any conventional thruster. // Photo Tom Servais

While the Internet was still lit up on Kai’s infinite loop and the endless possibilities of a new form of surfing, the biggest lashback came from Facebook when big wave charger Jamie Mitchell posted an unnerving mugshot of a Japanese surfer with a monster laceration across his forehead and warned of foilboards infiltrating lineups and posing dangers to surfers around the world.

Kai points out that the Japanese surfer pictured was using a traditional kite foil which is much sharper compared to the strategically designed blunt edges on his Aguera GoFoil. Kai is the first one to clarify that foilboards are not meant to be in crowded lineups because they present additional risks and demand so much more space. The reality is that foil surfboards are designed to ride the mush-ball mysto-wave that’s bearly breaking farther down the beach or a bit more off shore. According to Kai, “It’s not about paddling into a lineup when the surf is good, it’s about escaping the paddle battle, opening up the surf horizon and finding your own wave.”

Kai Lenny kickstarts the next chapter of hydrofoiling by prone paddling into one wave and riding the next three back-to-back. With plenty of room for innovation, the foilsurfing game has only just begun. // Photo Tom Servais

Kai Lenny kickstarts the next chapter of hydrofoiling by prone paddling into one wave and riding the next three back-to-back. With plenty of room for innovation, the foilsurfing game has only just begun. // Photo Tom Servais

Thanks to Kai, watermen around the world can steadily become one step closer to eradicating the condition gap and arm themselves with a new tool for the trade. Even if the foil doesn’t solve all our problems, it does open up a whole new world of wave options, taking us to frontiers that surfers have long ignored and finally delivering the proper equipment necessary to explore hydrofoil kitesurfing.


Words by Brendan Richards

This article was featured in the fall 2016 issue of The Kiteboarder Magazine.


Read about the designer of Kai’s foil, Alex Aguera and the evolution of his GoFoil company in Tkb’s spring 2017 issue, vol 14. no 1. Available now. Subscribe here: ow.ly/frVc305a8jk