Big Island police identified a 46-year-old man believed to have drowned in Kau as Derek Hara of Pahala.
Kau patrol officers responded at 12:11 p.m. Wednesday to a reported drowning near the Rancho subdivision in Ocean View.
Hara had been diving in an area called Osaka Flats with two companions, who found him unconscious. Fire rescue personnel responded but were unable to revive him.
An autopsy is scheduled to determine the cause of death.