An anti-submarine missile is a standoff weapon including a rocket designed to rapidly deliver an explosive warhead or homing torpedo from the launch platform to the vicinity of a submarine.
Depth charges were the earliest weapons designed for use by ships against submerged submarines. These explosives were initially dropped as the ship moved over the presumed location of a submarine; but shipboard SONAR was unable to maintain contact with the submarine at close range. Various mortar-type projectors (including hedgehog and squid) were devised during World War II to allow a ship to maintain SONAR contact while lobbing explosive charges toward the submarine.[1] During the cold war, rockets were developed to provide greater range with reduced recoil. Some rockets carry homing torpedoes to provide terminal guidance for the warhead.[2]