Abstract: An apparatus for destroying a target underwater object includes a targeting system and a gun system. The targeting system has a laser which produces a laser beam, a laser ranging sensor sensitive to reflections of the laser beam from an underwater object, and electronic circuitry that determines the position of a target underwater object using an output signal of the laser ranging sensor. The gun system includes a gimballed gun that fires a projectile and is pointed at the underwater target by the targeting system. The targeting system may be operated to track the projectile in the water as well as the target to be destroyed and to correct the aim of the gun according to the relative position of the target and the projectile.