Exercise bias understates destroyer air defence

Interwar exercise pilots repeatedly ignored destroyers to attack carriers and capital ships because simulated losses carried no mortal cost. That behavior encouraged navies to treat destroyer guns mainly as low-angle barrage weapons. These mounts were lighter and simpler to maintain, reducing crew hours while fitting treaty displacement limits. Their lower weight also left room for torpedoes, depth charges, ASDIC, and subdivision. Admiral Henderson questioned whether the exercise results were too favorable, while a similar challenge in the U.S. Navy is tentatively associated with Admiral King. Japanese anti-aircraft specialists also questioned the lessons. Navies that entered the war before making corrections faced the consequences when aircraft attacked the destroyers themselves.