Dan Carlock, 45, was left by his diving group Sunday as he drifted for hours about seven miles offshore. He noted the time of day on his small, waterproof writing slate and took photographs of himself to document that he'd made it to the surface.
Carlock, a former Boy Scout, recalled his survival manual: Stay calm. Think methodically. Still, he worried about how his parents would react to his death.
He said he prayed "God, I don't want to die," and "I want to be saved. I need your help."
The spacecraft engineer for Boeing Satellite Systems and three dive buddies entered the water at about 8:45 a.m. Sunday, but Carlock had problems equalizing the pressure in his ears and he fell behind. He tried following his partners' bubbles, but he lost them.
He decided to end the dive after 15 minutes, but he was 400 feet down current from an oil platform where the boat was anchored. He blew his whistle to attract attention.
"I figured when the dive was over they would realize I was missing and come looking for me," Carlock said.
But they never came. The boat left and headed for a shipwreck six miles southeast of the entrance to the Port of Los Angeles, said Coast Guard Petty Officer Collin Croft.
Five hours later, crew trainee Zack Mayberry, 15, stood watch on the stern of the tall ship Argus, which was full of Boy Scouts. The ship had changed course because of heavy fog.
Mayberry saw something in the water and grabbed his binoculars: About 150 yards away, Carlock's head was sticking out of the water. Mayberry handed the binoculars to a friend.
"I wanted to make sure my eyes weren't playing tricks on me," Mayberry said.
The San Diego Boy Scout troop had drilled the rescue procedure the previous day and the rescue operation began. A small motorboat was sent to pluck Carlock from the sea and he was brought aboard.
Coast Guard officials Tuesday said they are investigating why Carlock was left behind, then not reported missing until his group reached the second dive location at 12:03 p.m.
The Coast Guard, the recreational diving instructors, Long Beach lifeguards and Los Angeles City Fire Department personnel searched for Carlock near the second dive location until learning of the rescue.
Ocean Adventures Dive Co. owner Steve Ladd says he is trying to figure out what happened.