WWII US Navy aircraft carriers defended with a layered anti-aircraft (AA) system, evolving from early, less effective .50-cal machine guns and 1.1-inch guns to highly effective Bofors 40mm and Oerlikon 20mm cannons, often paired with revolutionary Mk 14 gunsights and proximity-fused (VT) shells for the larger 5-inch guns, countering threats like dive bombers and kamikazes. These weapons were strategically placed around the flight deck and island for maximum coverage, especially vital as carriers