Making Waves

Summer will soon be here, and surfers will head to spots all over the world to catch the perfect wave. But if conditions aren’t just right, they might encounter a calm ocean with no surf. What a bummer! World-champion surfer Kelly Slater hopes to make a disappointing lack of waves a thing of the past. With the help of an engineer, he built a machine that can create artificial waves ideal for surfing anytime and anywhere—even in places far from shore.

The invention can be found at the Kelly Slater Wave Company Surf Ranch, located in Lemoore, California. It’s 175 kilometers (109 miles) from the nearest beach. The facility was built on an artificial lake more than six football fields in length. The lake was formerly used for water skiing. Now it’s the first place in the world that uses a machine to produce waves like those found in the ocean.

Summer will be here soon. Surfers will head to spots all over the world to catch the perfect wave. But if conditions aren’t just right, they might find a calm ocean with no surf. What a bummer! World-champion surfer Kelly Slater hopes to end the disappointing lack of waves. With the help of an engineer, he built a machine that can make artificial waves. They’re perfect for surfing anytime and anywhere—even in places far from shore.

The invention is found at the Kelly Slater Wave Company Surf Ranch in Lemoore, California. It’s 175 kilometers (109 miles) from the nearest beach. The ranch was built on an artificial lake that’s more than six football fields long. The lake was once used for water skiing. Now it uses a machine to make waves like those found in the ocean. It’s the first place in the world to do this.

Slater hopes to open similar surf parks around the world that could provide endless waves for seasoned surfers and give those new to the sport the chance to give it a try. Manufactured wave systems like Slater’s could also be a game changer for professional surfing. Reading the ocean and waiting for the right wave to come along is a big part of surfing. But now, pro surfers can practice and even compete on artificial waves without having to worry about luck or timing.

“The facility’s reproducible waves level the playing field for every surfer,” says Jessi Miley-Dyer, the commissioner of the World Surf League (WSL). “It changes the focus from the ability of a surfer to pick the best wave to surf to a focus on perfecting and practicing skills and tricks.”

Slater hopes to open surf parks like this around the world. The parks could provide endless waves for skilled surfers, plus give new surfers a chance to try the sport. Artificial wave systems like Slater’s could also change professional surfing. Surfers have to read the ocean and wait for the right wave to come along. That’s a big part of the sport. But now, pro surfers won’t have to worry about luck or timing. They can practice and even compete on artificial waves.

“The facility’s reproducible waves level the playing field for every surfer,” says Jessi Miley-Dyer. She’s the commissioner of the World Surf League (WSL). “It changes the focus from the ability of a surfer to pick the best wave to surf to a focus on perfecting and practicing skills and tricks.”

Creating artificial waves that look and act like natural ocean waves has long been a challenge for scientists. The many artificial wave pools that exist around the world fall short. They create waves using paddles that sweep through the water or devices that shoot water upward. But those mechanically made waves don’t match the power, speed, or shape of natural waves produced by the sea (see How Ocean Waves Form).

It’s hard to make artificial waves that look and act like natural ocean waves. That’s been a challenge for scientists for a long time. Many artificial wave pools exist around the world, but they fall short. Some make waves with paddles that sweep through water. Others use devices that shoot water upward. But those artificial waves don’t match the power, speed, or shape of natural waves in the sea (see How Ocean Waves Form).

No one had successfully created a wave that could be surfed until Slater teamed up with Adam Fincham. He’s an engineer who studies fluid dynamics—how liquids and gases move—at the University of Southern California. Fincham approached the problem of making realistic artificial waves by first studying how actual ocean waves form and behave. He studied mathematical computations, computer simulations, and small-scale models.

Fincham knew that waves in the ocean sweep laterally toward the shore. So he needed a way to mechanically re-create this movement. He decided to use a hydrofoil—a fin-like device that moves through the water.

No one had found a way to make a wave that could be surfed. Then Slater teamed up with Adam Fincham. He’s an engineer at the University of Southern California. He studies fluid dynamics—how liquids and gases move. Fincham tackled the problem of making realistic artificial waves. First, he studied how real ocean waves form and act. He used mathematical computations, computer simulations, and models.

Fincham knew that waves in the ocean sweep sideways toward the shore. So he needed an artificial way to copy this movement. He decided to use a hydrofoil. That’s a fin-like device that moves through the water.

To test his hydrofoil, Fincham built a prototype wave pool. The model was about one-fourth the size of an Olympic-size swimming pool, and about 15 times smaller than what he expected the final wave pool to be.

Fincham connected the hydrofoil to a track system along the side of the prototype pool. Cables pulled the hydrofoil forward. When the device moved, water pushed against it, creating a slowing force called drag. Just as he had hoped, the shape of the hydrofoil disrupted the water and pushed it laterally to form a wave. “The hydrofoil moves underwater like a submarine,” says Fincham. “But a submarine is designed to produce as little drag as possible—we created a shape that maximizes wave drag.”

After several years of testing and tweaking the shape of the hydrofoil, Fincham successfully created a swell. This hump-shaped wave grows, or swells, as it rolls across the water’s surface.

Fincham built a model wave pool to test his hydrofoil. This prototype was about one-fourth the size of an Olympic-sized swimming pool. It was 15 times smaller than his plan for the final wave pool.

Fincham built a track system along the side of the prototype pool. He connected the hydrofoil to the track. When cables pulled the hydrofoil forward, water pushed against it. This formed a slowing force called drag. The shape of the hydrofoil disturbed the water and pushed it sideways to form a wave, just as Fincham had hoped. “The hydrofoil moves underwater like a submarine,” he says. “But a submarine is designed to produce as little drag as possible—we created a shape that maximizes wave drag.”

Fincham tested and changed the shape of the hydrofoil for several years. Finally, he created a swell. This hump-shaped wave rolls across the water’s surface and grows, or swells.

Next he needed to make the swell break. That’s when a swell grows so large that the crest of the wave spills over its front, forming a barrel, or tunnel, before collapsing. In the ocean, surfers ride on the face of a swell, as well as inside the barrel of a breaking wave.

To get his artificial waves to break, Fincham needed to shape the bottom of the pool to match the contours of a seafloor. In nature, seafloors have reefs or sandbars near shore that waves break against. Knowing that Slater had spent his life traveling the world to find beaches that formed the best surfing waves, Fincham asked Slater which contours might work best for the bottom of his pool. It took another full year of testing to create a breaking wave that could be reproduced over and over again.

Next he needed to make the swell break. That’s when a swell grows so large that the top of the wave spills over its front. It forms a barrel, or tunnel, before it collapses. In the ocean, surfers ride on the face of a swell. They also ride inside the barrel of a breaking wave.

To get his artificial waves to break, Fincham needed to shape the bottom of the pool like a seafloor. In nature, seafloors have reefs or sandbars near shore. Waves break against these features. Fincham knew that Slater had traveled the world for years to find beaches with the best surfing waves. So he asked Slater which shapes might work best for the bottom of his pool. He tested for another year. Finally, he created a breaking wave that could be formed over and over again.

In 2015, a full-sized version of Fincham’s wave pool was completed in Lemoore (see Creating Artificial Surf). A year later, the WSL purchased rights to the facility.

Then in September 2017, Slater invited some of the world’s top surfers, along with WSL commissioner Miley-Dyer, to try out the artificial waves for themselves. “Everyone who surfs it is blown away,” says Miley-Dyer. “Being so far from the coast, in the middle of a field, and to know that a perfect wave is coming each time—it’s such a cool thing.”

A full-sized version of Fincham’s wave pool was built in Lemoore in 2015 (see Creating Artificial Surf). The WSL bought rights to the place a year later.

In September 2017, surfers got a chance to try out the artificial waves. Slater invited some of the world’s top surfers, along with WSL commissioner Miley-Dyer. “Everyone who surfs it is blown away,” says Miley-Dyer. “Being so far from the coast, in the middle of a field, and to know that a perfect wave is coming each time—it’s such a cool thing.”

After the overwhelming success of the event, the WSL decided to add the Surf Ranch as a new stop on the WSL Championship Tour this coming September. It’s the first time an artificial wave pool will be featured as a site for a pro-surfing competition.

Miley-Dyer hopes the technology will help professionals practice their skills and draw more people to the sport. “Surfers have never had training facilities with consistent conditions like other athletes,” says Miley-Dyer. “I definitely believe that access to facilities like these will allow skill levels to skyrocket in a short amount of time.”

The event was a huge success. So the WSL added the Surf Ranch as a new stop on the WSL Championship Tour this coming September. It’s the first time a pro-surfing competition will be held at an artificial wave pool.

Miley-Dyer hopes the invention will help professionals practice their skills. It could also introduce more people to the sport. “Surfers have never had training facilities with consistent conditions like other athletes,” says Miley-Dyer. “I definitely believe that access to facilities like these will allow skill levels to skyrocket in a short amount of time.”