A snorkeler who was found unresponsive at Pokai Bay in Waianae Thursday has died.

The Honolulu Medical Examiner’s Office identified him as 54-year-old Christian Boulden of Maryland. The exact cause of his death is pending.

Honolulu Ocean Safety and Emergency Medical Services personnel as well as police and firefighters responded to a call of an unresponsive snorkeler in waters fronting the Pililaau Army Recreation Center at about 5 p.m. Thursday.

A paddle boarder noticed the man was not moving and started bringing him to shore.

Shayne Enright, spokeswoman of the Honolulu Department of Emergency Services, said a lifeguard swam to them and brought the snorkeler later identified as Boulden to shore.

Lifeguards and firefighters performed cardio pulmonary resuscitation until EMS arrived.

Paramedics conducted advanced life-saving treatment and took him in critical condition to a hospital where he died.