The Sting Ray is a British acoustic homing lightweight torpedo (LWT) manufactured by GEC-Marconi, who were later bought out by BAE Systems.

A design for a British Mk 31 torpedo which would have used active echo-location sonar failed to receive Government approval for production.

The homing system developed in the mid-1960s incorporated a spinning magnetic disc onto which the acoustic correlation algorithms were etched but this was replaced by integrated circuit technology when the disc sometimes failed to survive the impact of the weapon with the sea from high altitude launches.

The original in-service version (Sting Ray Mod 0) is officially documented as entering service in 1983, although Higgitt [3] states that operational Sting Rays were loaded onto HMS Ardent under conditions of great secrecy immediately prior to sailing for the Falklands on 19 April 1982; Blackman's history of the Nimrod [4] also states that the aircraft flying from Ascension Island in 1982 were equipped with the weapon.

The propulsion method combines high speed, deep diving, agility and low noise levels.

Once launched it operates autonomously, with tactical software searching for the target using active sonar and then homing in without any further assistance.

[1] Sting Ray Mod 1 is intended for use against the same targets as Sting Ray Mod 0 but with an enhanced capability against small clad conventional submarines via a shaped-charge insensitive explosive warhead from TDW, and an improved shallow-water performance.