Seen as the replacement to the long lived US SUBROC and ASROC Anti-Submarine Weapons Systems, the planned UUM-125 ''Sea Lance'' was first designed and tested in 1980 by The US Navy. The Project (for Surface Craft deployment) was developed by The Boeing Aircraft Company. If successful, a RUM-125A Version, which would have been deployed via Submarine (surface) launch. ''Sea Lance'' was to be control via digital fire control similar to the (then) in use – Mark 50 Honing Torpedo. The weapon weighed 3,800-pounds and was 21-feet in length (with a diameter of 21-inches). Powered by a Hercules EX-116 Solid Fuel Rocket Booster, The ''Sea Lance'' would have achieved an air speed of Mach 1.5. The UUM-125 was rated as a tactical Nuclear Weapon and carried The W89 Warhead. This device could yield 200-Kilotons. By 1989, ''Sea Lance'' was converted into the previously theorized Submarine launched Missile. Later, the deployment of The W89 Warhead was removed, and the weapon proceeded with conventional explosives. By 1991, ''Sea Lance'' was canceled – with only prototypes created.