The "Alpha flag" is a maritime signal flag used in the International Code of Signals. It is represented by a blue and white checkered pattern and is used to indicate that a vessel is "diving" or that divers are in the water. This flag serves to alert other ships to maintain a safe distance to ensure the safety of the divers. When the Alpha flag is displayed, it is crucial for nearby vessels to recognize its meaning. The flag is part of a broader system that includes other flags, such as the Bravo flag for indicating dangerous cargo, ensuring effective communication at sea.