Blue ensign is a term that refers to a specific type of flag or ensign. This type of flag is usually blue in color and is often used to represent various maritime organizations, such as naval fleets or merchant ships. Some synonyms for the blue ensign include naval ensign, marine ensign, and seafaring banner. Other related terms might include flags such as the red ensign (used by merchant vessels in some countries) or the union jack (a flag that combines elements of the flags of England, Scotland, and Ireland). Regardless of the specific term used, each of these flags plays an important role in representing various aspects of maritime culture and history.