HMS Campania was a seaplane tender and aircraft carrier, converted from an elderly ocean liner by the Royal Navy early in the First World War. After her conversion was completed in mid-1915 the ship spent her time conducting trials and exercises with the Grand Fleet. These revealed the need for a longer flight deck to allow larger aircraft to take off, and she was modified accordingly. Campania missed the Battle of Jutland in May 1916, but made a number of patrols with elements of the Grand Fleet. She never saw combat and was soon relegated to a training role because of her elderly machinery. In November 1918 Campania was anchored with the capital ships of the Grand Fleet when a sudden storm caused her anchors to drag. She hit several of the ships and the collisions punctured her hull; she