Alert people at a North Shore beach last week set in motion an ocean rescue of an inexperienced swimmer in 10- to 15-foot surf.

Greg Gerstenberger said he knew instantly that the man who had jumped into the water at Ke Iki Beach at Pupukea was headed for trouble, and called 911.

Beachgoer Emmett Nothnagle said he became worried when he saw the man walking toward the waves. Nothnagle ran to change from work clothes to a swim suit, grabbed his fins and dove in after the man.

Lifeguard Brendan Shea got the call while patrolling nearby and arrived within 30 seconds, said Gerstenberger, the manager of Ke Iki Beach Bungalows, a vacation rental business.

The swimmer, who had lost consciousness after being under water, was rescued and taken to the hospital, Gerstenberger said.

"Luckily all these things worked together to perfection," he said. "If there was any lapse in anything the guy would have died."

Gerstenberger said the swimmer, who wasn't wearing fins, jumped in the water when the wave sets were small, probably thinking it was safe. But it was clear to Gerstenberger that the swimmer didn't know how to handle waves.

Gerstenberger said he didn't hesitate and called 911.

Meanwhile, Nothnagle was running into the surf after the swimmer just as the waves started to get bigger.

Nothnagle collared the man within 30 seconds but a set of waves hit them and they became separated, he said. The wave brought Nothnagle to shore. The swimmer, who appeared exhausted, was hit by another wave and sucked out to sea, Gerstenberger said.

"The next wave that hit him, he didn't come up," he said.

By then Shea, patrolling on a personal watercraft at Three Tables, had received the 911 call and arrived at the scene. At first the lifeguard thought Nothnagle was the person in trouble, Gerstenberger said.

Nothnagle had lost his fins but swam out to look for the swimmer again, said Robert Snelling, who had gone to the beach to check out the waves after work. Shea and Nothnagle searched for 30 or 40 seconds and it looked like the swimmer was gone for sure, Snelling said.

"The swimmer's body miraculously surfaced right in front of Emmett and the lifeguard," Snelling said. "They got his lifeless body on the Jet Ski sled and beelined for the beach."

Two other lifeguards had arrived by then and the team worked to save the man's life as his wife and friend stood by, Snelling said.

Nothnagle praised the team of lifeguards; his neighbor, Gerstenberger; and Shea for saving the man's life.

He said he visited the swimmer, who is in the Air Force, at Tripler Army Medical Center.

"I was just a piece of the puzzle that worked itself together for him to be still alive today," Nothnagle said. "Without Greg calling for help, without Brendan Shea who showed up on the scene and jumped into action and without the response team on the beach that helped revive his heart and got him to breath, none of this would be possible."