33. South Uist. (NF 752 429), (NF 777 406)

The major military facility on South Uist is the missile range, which is controlled by QinetiQ at RAF Benbecula[12]. There are a number of sites throughout the island, including the rangehead, complete with missile launch areas, at West Geirinis. The range control is situated at Ruabhal, and the summit of the hill has been tagged "where religion meets radar" as the control centre was built alongside a 30ft statue of the Madonna and Child called 'Our Lady of the Isles'. The hill top site encompasses a number of buildings and domes.

In March 2004, it was revealed that in a declassified 1981 report, the Naval Radiation Protection Services discovered that the rangehead and its surrounding area had been contaminated between 1967 and 1980 by high amounts of Cobalt-60, a radioisotope used to track missiles. In this thirteen year period, the Cobalt-60 was leaked onto the launch pad over one hundred times, a dangerous situation that may have caused harm to a large number of people. The report concluded that " both the ammunition technicians at RA Range Hebrides and possibly the general public were being placed at unnecessary radiological risk by the inadvertent consequences of Radio Mist Distance Indicators operations." In addition, the report noted that the land and sand dunes outside the base may have been contaminated but because no evidence of the isotopes was found, the land was not included in the decontamination process. An earlier investigation by the West Highland Free Press in 2002 had found that the 352 drums of waste from the decontamination process were buried at the range.

Also on South Uist are a sea watch radar station at Sheaval and a patrol boat mooring at Lochboisdale.