Nautical flags are colorful flags used at sea to communicate important messages between ships. Each flag represents a letter of the alphabet or a specific message, allowing sailors to convey information without using radio or other electronic means. These flags are part of the International Code of Signals, which standardizes maritime communication. In addition to individual letters, certain combinations of flags can signal specific instructions or warnings. For example, the Alpha flag indicates a vessel is diving, while the Bravo flag signals that a ship is handling dangerous cargo. Nautical flags are essential for safe navigation and coordination at sea.