 This heavy gun armament was provided in case she was surprised by enemy cruisers and forced to give battle, but her large and vulnerable flight deck, hangars, and other features made her more of a target in any surface action than a fighting warship.Carrier doctrine was still evolving at this time and the impracticability of carriers engaging in gun duels had not yet been realized.She was given an anti-aircraft armament of six twin 45-caliber 10th Year Type Model A2 gun mounts fitted on sponsons below the level of the funnels, where they could not fire across the flight deck, three mounts per side.