Hurricane Warning Flags If you see THESE flags flying, you'd better head for shelter. For over 100 years, yacht clubs, marinas, and Coast Guard stations hoisted flags, pennants and colored lights to warn mariners of storms at sea. On February 15, 1989, the National Weather Service discontinued this nationwide Coastal Warning Display network in lieu of NOAA marine weather forecasts delivered via marine VHF and HF radio and the Internet. On June 1, 2007, the U.S. Coast Guard re-established a Coastal Warning Display program at selected small boat stations. They continue the tradition of hoisting display flags to warn of small craft advisories, gale warnings, storm warnings and hurricane warnings.