Around 9:45 a.m. Sunday, Ocean Safety, Emergency Medical Services and the Honolulu Fire Department responded to Sharks Cove on the North Shore for a near-drowning.
Bystanders had already pulled the oceangoer, a visitor from Utah in his 40s, out of the water and onto shore.
Lifeguards and HFD performed CPR. According to bystanders, the man was snorkeling when he ran into trouble.
The man regained a pulse and began breathing. EMS continued treatment and transported him to the emergency room in critical condition.
He was later pronounced dead. There were no signs of foul play.