High Quality Content by WIKIPEDIA articles! The Shetland Bus was the nickname of a clandestine special operations group that made a permanent link between Shetland, Scotland, and German-occupied Norway from 1941 until the German occupation ended on 8 May 1945. From mid-1942 the official name of the group was "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).