ASROC. It was a missile that IIRC went up to 40km, then plunged into the ocean, detonating at some depth. A countermeasure to nuclear cruise missile boats, whic

ASROC. It was a missile that IIRC went up to 40km, then plunged into the ocean, detonating at some depth. A countermeasure to nuclear cruise missile boats, which could launch from considerable distances.