SAN DIEGO – A recovery effort resumed Wednesday to locate a missing 18-year-old man who was pulled into the ocean a day ago near Mission Beach.

The teen was spotted about 3:30 p.m. Tuesday by a San Diego Fire-Rescue lifeguard near Tower 16, agency spokeswoman Mónica Muñoz said. Lifeguards say he was part of a group of high school students at the beach on their last day of school in a period when the surf was bigger than usual.

Crews rescued two other teens from the ocean, but the missing man went underwater and did not resurface, Muñoz said, prompting a series of rescue and recovery efforts at the beach.

Eighteen San Diego Lifeguards staffers were working to recover the man Wednesday morning.

“Lifeguards have three rescue vessels and rescue water craft conducting scuba searches using sonar equipment,” Muñoz said. “The teams plan to conduct two dives this morning just outside the surf line.”

Also assisting in the day’s efforts were crews from the U.S. Coast Guard, which has both a cutter and a helicopter working the area.

The first Coast Guard search was conducted this morning with the next coming at 5 p.m., Muñoz said.

In the interim, a memorial was set up near Tower 16 featuring red, pink and white roses, the No. 21 spelled out with seashells and a heart drawn in the sand with the letters “WZ.” Those are believed to be the missing swimmer’s initials and his high school basketball number.

The man has not been publicly identified by authorities.

FOX 5’s Jacqueline Sarkissian and Domenick Candelieri contributed to this report.