The Ocean City Police Department alerted Coast Guard personnel to the missing boy shortly before 7 p.m.
The boy was swimming with friends when they were all swept out by a rip current. All of the boys except the 14-year-old were able to return to shore, according to the Coast Guard.
Those searching for the boy include: a 25-foot response boat, with Coast Guard crew, and an MH-65 Dolphin helicopter crew from Coast Guard Air Station Atlantic City.
Others searching include: the New Jersey State Police Marine Unit; the Ocean City Fire Department; and several "good samaritans," according to the Coast Guard.
He is reported to be wearing white swimming shorts.