A swimmer who disappeared off the coast of Ocean Beach Tuesday remains lost this morning, as officials resume their search off the San Francisco coast.

According to a tweet by the San Francisco Fire Department, a "reported victim in water" was called into 911 at 7:34 p.m. Tuesday evening.

KRON 4 reports that the person, about whom officials have released no identifying details, was seen in the water near the Cliff House restaurant.

"Thick fog and low visibility hampered with search efforts," KRON 4 reports, as crews with the SFFD and Coast Guard searched the water.

After an hour of effort, the Chron reports that rescuers "found no sign of the victim" and called the search off for the night.

NBC Bay Area reports that the effort will resume Wednesday this morning, and that "A helicopter may join the search effort Wednesday depending on visibility."

Related: Tourists And Selfie-Takers Need To Stop Going Near The Cliffs And Caves Near The Cliff House