A tracking ship, also called a missile range instrumentation ship or range ship, is a ship equipped with antennas and electronics to support the launching and tracking of missiles and rockets. Since many missile ranges launch over ocean areas for safety reasons, range ships are used to extend the range of shore-based tracking facilities.
In the United States, the initial tracking ships were constructed by the U.S. Army and then the U.S. Air Force to support their missile programs. They were generally built on a surplus Liberty ship or Victory ship hull. By 1964, the U.S. Navy took over all the range ships and introduced more.
In some Navies, such a ship is also given the Type Designation "Vigilship" or "Veladora", with the Designation Letter "V" or Letters "VC".