An anti-submarine weapon (ASW) is any one of a number of devices that are intended to act against a submarine and its crew, to destroy (sink) the vessel or reduce its capability as a weapon of war. In its simplest sense, an anti-submarine weapon is usually a projectile, missile or bomb that is optimized to destroy submarines.
A Hedgehog depth charge launcher
Mk. 17 depth bomb is being unloaded from a SOC Seagull scout plane on board the USS Philadelphia (CL-41) during an Atlantic U-boat sweep near Panama in June 1942.
Hedgehog, a 24-"barreled" anti-submarine mortar, mounted on the forecastle of the destroyer HMS Westcott, 28 November 1945. The 27-year veteran Westcott claimed the first-ever kill by Hedgehog February 2, 1942, when she sank U-581.
A U.S. Navy depth charge, used in WWII
A missile is an airborne ranged weapon capable of self-propelled flight aided usually by a propellant, jet engine or rocket motor.
A V-1 flying bomb, amongst the first guided missiles
A semi-active missile homing system
A Tomahawk cruise missile in flight
An Exocet Anti-ship missile in flight