Torpedo

The torpedo, is an explosive projectile weapon that moves by itself (using a propeller), launched above or below the water surface, that goes underwater toward a target, and made to explode when it hits a target or is near to it. Torpedoes may be launched from submarines, surface ships, helicopters, aircraft, land etc. Robert Whitehead invented the torpedo in 1866.

Other websites

Swedish Bofors 'Torpedo 2000' promo video
Modern Torpedoes And Countermeasures Archived 2012-02-22 at the Wayback Machine
US Navy torpedo data cut and pasted from a Navy Fact File Archived 2005-11-04 at the Wayback Machine
Early History of the Torpedo Torpedo History
US Naval Undersea Museum Torpedo Display Archived 2005-09-08 at the Wayback Machine
US Naval Undersea Museum Torpedo Collection Archived 2005-02-26 at the Wayback Machine