Making Waves

Reefs: Science and surfing meet in the infant industry of artificial reef design, meant to enhance nature's waves.

Medicine & Science

October 13, 2003|By David Kohn | David Kohn,SUN STAFF

Randy Meyer has ridden waves all over, from Hawaii to Costa Rica. So, when he looks at the jumbled, puny "junk waves" that often roll shoreward in Ocean City, he can't help longing for the smooth, steep monsters of the Banzai Pipeline or Malibu.

But Meyer, who surfs at Ocean City several times a week in season, isn't content to dream of far-away shores. He wants to bring a version of those world-class waves to the Delmarva coast.

How? By constructing an artificial surf reef, a cutting-edge structure that supporters say can sculpt O.C. "junk waves" into the real thing. By changing the "bathymetry," as underwater topography is known, coastal engineers say they can adjust the waves that roll over it, creating consistent, ride-able swells.

"It's a surfer's dream," said Meyer, an Eastern Shore resident who is trying to persuade local officials to build such a reef off Ocean City. "You're making the wave you want. It's like having an amusement ride out in the ocean."

Believers say the reefs could transform surfing. "There are thousands of beaches around the world where, with a small amount of modification, you could create a good wave," said Kerry Black, 52, an oceanographer, surfer and leading artificial-reef proponent.

Building reefs to pump up waves is not a new idea. But only in the past decade has wave measurement technology advanced to the point where it's feasible.

Black began building better waves in the early 1990s, when he was a professor at New Zealand's University of Waikato. To pinpoint the factors that produce good swells, he and several grad students traveled the Pacific Rim from California to Indonesia, analyzing 46 top spots.

The researchers used sonar to map the seabed topography and video to measure a range of wave characteristics, including speed, height and "peel" (the timing of a wave's break). After analyzing the data, they developed formulas to quantify the characteristics of a top surf wave.

They found that wave shape depends largely on the contour of the near-shore seabed. The most important variable, oceanographers say, is the slope of the bottom. A steeper rise generally produces a better wave. As a wave starts running into the shore, it slows. If this slowing happens rapidly, the wave will rise up, creating the plunging mass of water that surfers love.

"The top of the wave is going so much faster than the bottom that it creates this big barrel, like the Banzai Pipeline in Hawaii," said Dave Skelly, an Encinitas, Calif., coastal engineer who has designed artificial surf reefs.

The other key is the peel angle. Surfers like a wave that doesn't break everywhere at once. If the wave "peels" off, breaking sequentially, surfers can ride the unbroken face as it tumbles, carving a longer, faster path that, at best, is almost parallel to the shore.

Armed with this information, Black started Artificial Surf Reef Ltd. (ASR) in 1997, hiring four of his students to help him. He set up shop in Raglan, a western New Zealand beach town known for its natural waves. When the surf is good, he and most of his employees head for the beach, and work at night.

To plan a reef, Black measures a given spot's waves, currents and tides, and then adjusts the formulas to fit those specifics. Seen from above, the reef will eventually look like a large arrowhead with two beveled sides, facing the oncoming waves.

Made from hundreds of precisely stacked giant sandbags, the structure raises the point of impact between wave and seabed, while the triangular shape keeps the wave from breaking all at once, producing a pleasing peel.

It sounds good in theory, but the science is still in its infancy. Just three of the structures exist, all built in the past six years. Of those, only one, off Narrowneck beach in Sydney, Australia, has been a clear success.

"There's a lot of naive optimism out there," said Chad Nelsen, environmental director for Surfrider, a group dedicated to preserving coastlines, particularly surfing beaches. "This taps into the secret fantasy of every surfer, but it's an unproven technology."

Nelsen argues that protecting existing surf spots from pollution, erosion and development should take precedence over improving mediocre waves.

Proponents counter that artificial reefs can also control shore erosion much more efficiently than jetties, sea walls and "renourishment" efforts that dump piles of sand on the beach. The structures also create an inviting habitat for marine life, including fish, plants and crustaceans, Black says.

But even cheerleader Skelly, who foresees a day when surf engineers will use genetically engineered coral, concedes that wavemaking is still more art than science. "Waves in the real world are only a little bit like waves in the lab," he said. "There are so many variables - different tides, waves coming in at different directions, different bottom types. You're never going to be able to go to Home Depot and buy a surf spot."

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