Crews from the North County Fire Authority and U.S. Coast Guard responded around 10:45 a.m. to a water rescue at Manor Beach, near Esplanade Avenue.
Two hours later, authorities said they were still on scene and conducting a full search for young man who went into the water and did not resurface.
San Francisco State University told KTVU in a statement that the person crews were searching for is a student at the university.
"We are aware of reports of a search for an SF State student in the waters off Pacifica. The entire SF State community is hoping for a safe recovery. Our thoughts are with the student’s family, friends and classmates. We are grateful to the Coast Guard and the Pacifica Police Department for their ongoing work," the university said.
Several members of the San Francisco State University wrestling team told KTVU that the missing student is their friend, but they wouldn't elaborate any further.
Firefighters said there are strong rip currents in the area that can take down just about anyone, even an athlete in good shape.
Those familiar Manor Beach said it drops off dramatically just offshore.
"Unfortunately today, there's large rip currents," said Jeff Huntze from North County Fire. "This area poses large rip currents just on a calm day, and today the waves are pretty big."
Crews wrapped up Thursday's search for the student just before sundown.