Search crews are looking for a swimmer who went missing in an area near 20th Street in Ocean City.
Beach Patrol officials rescued three swimmers from a group that put out distress signals at about 8 p.m., but crews were unable to locate the fourth person, said Steve Price, a Fire Department spokesman.
Patrol personnel made 250 surf rescues Saturday, Price said. While crews usually quit at 5:30 p.m., he said a "skeleton crew" remains until 8 p.m. because of increased danger.
Tropical storms in the Atlantic Ocean are contributing to a rough surf along the 10-mile stretch of Ocean City and a higher frequency of rip currents, according to Beach Patrol officials.
Swimmers should "swim near stations occupied by patrol personnel," Price said.
jkanderson@baltsun.com