The Shetland Bus (Norwegian Bokmål: "Shetlandsbussene", def. pl.) was the nickname of a clandestine special operations group that made a permanent link between Mainland Shetland in Scotland and German-occupied Norway from 1941 until the surrender of Nazi Germany on 8 May 1945. From mid-1942, the group's official name was the Norwegian Naval Independent Unit (NNIU). In October 1943, it became an official part of the Royal Norwegian Navy and was renamed the Royal Norwegian Naval Special Unit (RNNSU). The unit was operated initially by a large number of small fishing boats and later augmented by three fast and well-armed submarine chasers – , and .