Garrett McNamara, a 48-year-old surfing legend, once surfed a 100-foot wave off the coast of Portugal. On Thursday, the wave gods got retribution.

Surfing on his own with competition at Mavericks in Half Moon Bay, Calif., postponed by the aftereffects of big storms, McNamara was tossed like a piece of litter in the wind, smacking the water several times as he came off his board. The video of one of the worst wipeouts is just horrifying and, amazingly, McNamara was not seriously injured.

The biggest waves were estimated at 50 feet, according to the San Francisco Chronicle. It was a windless day, but the water was choppy from recent El Nino-related storms and few surfers dared to go out. McNamara was paddle surfing rather than tow-surfing with a jet ski assist.

About halfway down the drop, McNamara went down, hard, and as San Francisco surfer Grant Washburn described it, “He skipped like a stone and flew into the air,” at one point getting so dramatically airborne, it resembled a man being catapulted off a trampoline. Then, to make matters worse, McNamara was crushed underneath the wave’s massive lip.

“Shocking,” said Washburn. “Maybe one of the worst wipeouts ever filmed.”

McNamara was described by the Chronicle as “badly shaken” and underwent surgery on his arm and shoulder. Videographer Chris Wilson can be heard saying, “Oh, my God” over and over on the video and deconstructed how McNamara could have been killed in the surreal scene.

“It looked like it was made for him,” [photographer Curt] Myers says. But the wind blowing up the wave’s face was just too much. The nose of McNamara’s 20-plus-pound board lifted into the air.

As a safety precaution, McNamara had partially inflated his rescue vest. But this meant that, when he hit the water, rather than penetrating, he bounced. The wave landed on him, breaking and dislocating his shoulder and plunging him beneath a cascade of whitewater.

[Surfer Ion] Banner skied in to snatch up McNamara but came away empty. McNamara hadn’t reached for the rescue sled. His arm was dangling by the skin and sinew. Then Myers went in. “The thing to do when a surfer’s immobile is to grab him by the hand and pull him up,” Myers says. “But I wasn’t expecting that his arm was dislocated. It took a couple of passes to realize that he couldn’t do it. By then, his back was almost up to Mushroom Rock with the high tide draining off it. It was just frightening.”

Banner, at great personal risk, leapt off his ski and dragged McNamara onto the sled, then throttled out of the impact zone. Soon, a disoriented McNamara was loaded into an ambulance. “He asked, ‘What happened? What did I do?’” Myers says. “He was still concerned about making the wave.” McNamara underwent surgery for a badly broken arm and shoulder on Friday.