Lifeguards combed a stretch of Tourmaline Beach into Thursday morning searching for a surfer who disappeared off the coast Wednesday evening.
Lifeguards say the surfer was last seen on paddling on a board about 300 yards off the beach, a half-mile north of Crystal Pier.
Rescuers recovered a wetsuit tied to a surfboard, but no signs of the missing person.
"Lifeguards thought [the surfer] may be having difficulties," said Lt. John Everhart, who is with San Diego Lifeguards."Lifeguards down at the beach were able to spot someone briefly, saw a surfboard in the water, and then lost sight of them."
The U.S. Coast Guard used an MH-60 Jayhawk helicopter crew and a cutter in the search. Underwater divers were called off the search Wednesday night and will return Thursday morning to resume operations.
Lifeguards are also expected to release a photo of the recovered surfboard to help identify the missing surfer.