A stand-up paddler brought to shore a 68-year-old male visitor who was found unconscious Friday at the Hilton Lagoon.
Emergency Services spokeswoman Shayne Enright said the stand-up paddler spotted the man floating face down in the water.
Ocean Safety lifeguards found a pulse and began rescue breathing, Enright said.
Emergency Medical Services personnel transported the man in serious condition to a hospital.
The man had been snorkeling at the lagoon when he was found at 11:12 a.m. on the ocean side of the lagoon.