ABC News' Melissa Lustrin reports:

A snorkeler's near-drowning off a Hawaiian beach was caught on camera - but who exactly the snorkeler is remains a mystery.

The incident happened three weeks ago when the man went snorkeling off Paniau Beach in Puako. Overtaken by choppy waters, the snorkeler began to gasp for air and bob in and out of the water.

The snorkeler's struggle in the water was captured by his own head-mounted camera. The camera also captured the moment when a nearby surfer, Zach Soto, came to his rescue.

"Thirty seconds more - a 90 percent chance he would have died," Sato told local ABC affiliate KITV. "I yelled to see if he was okay. I could see he was kind of struggling. He put his hand up all the way and so I paddled there."

Sato described the snorkeler's condition as being, "Like pure blue kind of swollen and his eyes were barely like - almost rolled back," when he found him in the water.

The snorkeler survived thanks to Sato's actions, but he lost his camera in the sand after Sato and three other surfers pulled him to shore.

Two weeks later, another beachgoer found the camera in the sand, according to KITV. While Sato was identified as the rescuer, the snorkeler's identity remains a mystery.