USS Utah was a battleship that was attacked and sunk in Pearl Harbor on 7 December 1941. A Florida-class battleship, she was the only ship of the United States Navy to be named for the U.S. state of Utah. Prior to World War 2 she had declined in usefulness and had even served for a while as a mobile target for gunnery practice. In 1941, however, she had been refitted and was in use for training purposes when sunk by a torpedo in the Japanese attack.
Utah was laid down on 9 March 1909 at Camden, New Jersey, by the New York Shipbuilding Corporation. She was launched on 23 December 1909 under the sponsorship of Miss Mary Alice Spry, daughter of Utah Governor William Spry; and commissioned at the Philadelphia Navy Yard on 31 August 1911, Captain William S. Benson in command. (Wikipedia)
Semaphore flags are a system for conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands. Information is encoded by the position of the flags; it is read when the flag is in a fixed position. Semaphores were adopted and widely used in the maritime world in the early 1800s. Semaphore signals were used, for example, at the Battle of Trafalgar. This was the period in which the modern naval semaphore system was invented. This system uses hand-held flags. It is still used during underway replenishment at sea and is acceptable for emergency communication in daylight or, using lighted wands instead of flags, at night.