In December of 2015, a video appeared on the Internet that stunned surfers worldwide. Titled “Kelly’s Wave,” it showed Kelly Slater—arguably the best pro surfer in history—unveiling a secret project he had been working on for more than a decade. With the help of engineers and designers, Slater had perfected the first artificial wave, created by machine in a pool, that could rival the best waves found in the ocean. “One could spend years and years surfing in the ocean,” notes staff writer William Finnegan, himself a lifelong surfer, “and never get a wave as good as what some people are getting here today. Ever.”

Finnegan went to visit the Kelly Slater Wave Company’s Surf Ranch—a facility in California’s Central Valley, far from the coast—to observe a competition and test the wave for himself. Up until now, surfing was defined by its lack of predictability: chasing waves around the world and dealing with disappointment when they do not appear has been integral to the life of a surfer. But with a mechanically produced, infinitely repeatable, world-class wave, surfing can become like any other sport. The professional World Surf League, which has bought a controlling interest in Slater’s company, sees a bright future.

But Finnegan wonders what it means to take surfing out of nature. Will kids master riding artificial waves without even learning to swim in the ocean? Finnegan spoke with Kelly Slater, Stephanie Gilmore (the Australian seven-time world champion), and Matt Warshaw (the closest thing surfing has to an official historian). Warshaw, like Finnegan, is skeptical about the advent of mechanical waves. Yet he admits that, when he had the chance to ride it, he didn’t ever want to stop. “It reminded me of 1986,” Warshaw recalls. “The drugs have run out, you already hate yourself—how do we get more?”

William Finnegan’s article “Kelly Slater’s Shock Wave” appeared this month in The New Yorker.