Hawaii island police are investigating a reported drowning of a visitor Sunday morning in Hokulia Bay off Kailua-Kona.

At 9:30 a.m., Kona patrol officers and Hawaii Fire Department personnel responded to Keauhou Boat Harbor following a report of a possible drowning.

The 57-year-old man from Germany was participating in a guided snorkeling tour near Red Hill/Hokulia when he was observed to be in distress, according to a police statement.

Police said an employee of the snorkeling tour brought the unresponsive man on board and initiated CPR as the boat returned to Keauhou Boat Harbor, where HFD medics awaited.

Medics continued life-saving treatment as the man was transported to the Kona Community Hospital, where he was pronounced dead upon arrival.

Police have initiated a coroner’s inquest investigation to determine the man’s exact cause of death. No foul play is suspected. The man’s identity is being withheld pending notification of next of kin.

Police are asking witnesses to contact Kona Patrol Officer Collin Roberts at (808) 935-3311 or at collin.robert@hawaiicounty.gov.