A dive charter boat service at Stillwater Cove contacted the sheriff's office at 11:15 a.m. Monday to report an unconscious diver, later identified as 66-year-old David Michael Jones, sheriff's Detective Sgt. Archie Warren said.
Jones was in the ocean about 40 feet from the boat and had indicated to another diver that he was fine, when he suddenly went limp, Warren said.
He was pulled into the charter boat, where personnel began performing CPR on him, Warren said. A Monterey Fire Department boat arrived and transferred Jones to Community Hospital of the Monterey Peninsula.
CPR was performed on Jones for about an hour, but he was pronounced dead at the hospital, Warren said.
An autopsy by the coroner's office will help determine the cause of his death, Warren said.