A 47-year-old Tustin man drowned Saturday while scuba diving with two friends about half a mile off the San Clemente Pier, the Orange County Sheriff's Department reported.
The victim was identified as Lray Nield.
Sheriff's Lt. Larry Richey said that Nield was a certified diver in good condition and that his equipment was in good working order.
He theorized that the man died of natural causes.
An autopsy is scheduled today, according to Richard Slaughter, supervising deputy coroner.
Nield and two friends were diving in an area called West Reef about 11:30 a.m., Richey said, when one of the divers noticed that Nield was lying on the bottom of the reef in about 12 feet of water and that his mouthpiece was out of his mouth.
The two friends brought him up to the boat quickly and tried to give him first aid, but they were unable to revive him, Richey said.