OAHU, Hawaii — The Coast Guard and life guards are searching for a surfer who was last seen riding a 20-foot wave off the coast of Hawaii Wednesday afternoon.

Kirk Passmore, 32, was born in Orem and has been surfing for decades. He co-owned a surf shop in Oahu.

Passmore was surfing Wednesday near Haleiwa on the North Shore when witnesses said he was hit by two large waves, which broke his surf board apart, according to CNN. The surfboard was found down the beach.

Friends believe he suffered head trauma.

"He was seen swimming down with his feet up above the surface, and we think he broke his ear drum because what happens when you break your ear drum is you have complete loss of balance and you have vertigo," Jamie Sterling, a surfer who saw Passmore wipe out, told CNN affiliate KHNL. "So you have vertigo and he was swimming the opposite way and another wave came over him. And after that we didn't see any more of him, and we couldn't spot him."

Rescuers in helicopters and on jet skis searched the ocean for Passmore, but haven't found any signs of him.

There are reports Passmore was not wearing a float vest.

—Viviane Vo-Duc