Anti-submarine warfare History 5 World War, 1939-1945 5 Naval operations 4 Submarine 4 Military operations, Naval 3 Sea control 3 Aerial operations 2 Aircraft carriers 2 American 2 Campaigns 2 Defenses 2 Military campaigns 2 Naval operations, American 2 Naval operations, German 2 Naval research 2 Submarine warfare 2 Technological innovations 2 Aerial operations, American 1 Aeronautics, Military 1 Air defenses 1 Aircraft launching and recovery equipment 1 Civil defense 1 Flight simulators 1 German 1 Hydrophone 1 Military operations, Aerial 1 Naval operations, British 1 Radar 1 Submarines (Ships) 1