The body of a 21-year-old swimmer was recovered by lifeguards in waters off Redondo Beach Saturday, hours after he went missing near the shoreline, authorities said.

The man was identified by family as Marlon Fajardo of Lawndale, the Los Angeles Times reported.

Fajardo and his friends were swimming near the Knob Hill lifeguard tower (map) about 3:45 a.m. when they lost contact with him, according to a news release. His companions then called 911.

Personnel from multiple agencies — including the L.A. County and Redondo Beach fire departments, the U.S. Coast Guard and the Redondo Beach Police Department — responded to the scene.

Twenty lifeguards, four divers and five paramedics assisted in the search, officials said. Two helicopters and four rescue boats were deployed.

The dive team found Fajardo’s body at 10:06 a.m., in 18 feet of water, about 50 yards from where he had last been seen, the news release said.

“It’s not a happy ending, but at least it’s still good to know they found him,” the man’s grandmother, Louise Bernardez, told The Times. “I believed that he was gone. How long can you survive? Just a sharp minute.”

Although a high surf advisory was in effect at the time, rescuers said they did not believe surf conditions were a factor in Fajardo’s death.

“At that time, it was actually minimal and we were not getting the high surf that some of the other beaches are getting. … During all that time, the six hours, he didn’t move that far,” Redondo Beach Fire Department Chief Rob Rappaport said.

One-to 3-foot waves were reported at the time of Fajardo’s disappearance. He was not a strong swimmer, according to his friends.

The cause of the death is under investigation.