A 42-year-old diver died Monday off of Shaw's Cove. The cause of death was still undetermined as of Wednesday evening.
Mark Montague of Alta Dena and a female scuba-diving companion were about 100 feet yards off the beach, heading toward the rocks at the north end, when he complained of a problem with his equipment and the two headed back to shore, Lt. Jason Kravetz said.
A lifeguard spotted Montague face down in the water, Kravetz said.
"The lifeguard jumped in and pulled him out and immediately began administering CPR on the beach," Kravetz said.
Two more lifeguards arrived on the scene to assist. Paramedics, police and the Mercy helicopter also responded. The helicopter was waved off when no vital signs were detected.
Montague was pronounced dead about 40 minutes after the 12:50 p.m. call for help, Marine Safety Chief Kevin Snow said.
Paramedics work with a doctor at a base hospital to determine treatment and make the call on the cessation of vital signs.
Police suspect Montague suffered a heart attack, but the official cause of death is pending an autopsy.
"Prior to this there has never been a drowning death on a guarded beach in Laguna," Snow said.
Montague's enthusiasm for scuba diving was included on his website.