Flagship

In naval operations, a flagship is the vessel from which the senior officer of the formation commands. Admirals are termed "flag officers", for the distinguishing flag, showing their rank, when they are aboard or assigned to the vessel. The flag may also be distinguished, as, for example, when Admiral Chuichi Nagumo hoisted, on December 7, 1941, the same "Z" flag that Admiral Heihachiro Togo had hoisted to start the Battle of Tsushima in 1905.

In a very large formation, there may be flagships for the commanders of subordinate units. These flags may indicate rank (e.g., vice admiral), or, especially in the days of sail, an organizational identifier (e.g., rear admiral of the red [squadron]).

Flagship roles are sometimes symbolic rather than actual. HMS Victory, a wooden ship of the line built in 1765, is the official flagship of the United Kingdom Home Command. She served as the flagship of Horatio Nelson at the Battle of Trafalgar.

On taking command of the U.S. Pacific Fleet after the Battle of Pearl Harbor, Chester Nimitz, who actually directed operations from his headquarters ashore, formally took command on the deck of the submarine USS Grayling.