The U.S. Coast Guard searched Delaware Bay for about four hours Saturday after the crewman of a Singapore cargo ship was reported missing. The search, conducted by sea and air, covered 87 square miles but was called off shortly before 12 p.m. The water temperature is about 50 degrees, making it unlikely than anyone could survive in the water that long, a Coast Guard spokesperson said. The Singapore-flagged cargo ship, the Weco Josephine, reported the crew member missing around 7 a.m. The Coast Guard then dispatched a 29-foot response boat from its station in Philadelphia. A Coast Guard helicop…