A BatDiv or BATDIV was a standard U.S. Navy abbreviation or acronym for "battleship division." The Commander of a Battleship Division was known, in official Navy communications, as COMBATDIV (followed by a number), such as COMBATDIV ONE. One of the Battleship Divisions active during the First World War was United States Battleship Division Nine which augmented the striking power of the Royal Navy's Grand Fleet in 1917-1918.