The teen was reported missing around 5 p.m. Monday while boogie boarding near the 10th Street beach.
According to the U.S. Coast Guard, members of the Ocean City Beach Patrol rescued one person from the water.
That individual told responders the 19-year-old man had been on a boogie board before being struck by a wave and failing to resurface.
Chopper video showed roughly two dozen people forming a human chain in the water to assist in the search.
Crews search Ocean City beach after reports of missing swimmer
The search remains ongoing.
Authorities have not released the identity of the missing swimmer.