The "Alpha Flag" is a maritime signal flag used in the International Code of Signals. It is a blue flag with a white letter "A" in the center. This flag indicates that a vessel is requesting assistance or that a diver is in the water, signaling to other ships to keep a safe distance. In addition to its use in maritime communication, the Alpha Flag is also associated with the Nautical Flag System, which consists of various flags representing different letters and messages. Each flag has a specific meaning, helping sailors communicate important information at sea.