Hawaii County police are investigating the possible drowning of a 50-year-old San Francisco man whose body was found today along the Kohala Coast.

Paul S. Tsang was snorkeling in waters off Mauna Lani Beach Club about 12:35 p.m. when an unidentified person on shore noticed he was floating. An Ogden, Utah, man using a paddleboard went to check on Tsang and found him unresponsive. Tsang was brought to shore, where a nurse from Tucson, Ariz., and Hawaii lifeguard personnel performed CPR until Hawaii County Fire Department personnel arrived.

Tsang was taken to North Hawaii Community Hospital, where he was pronounced dead at 1:39 p.m.

Police are investigating the matter as a coroner’s inquest and have ordered an autopsy to determine the cause of death.