'Cygnus' was a British naval rescue mission by Lieutenant R. F. Seddon’s MGB-718 of the 15^th Motor Gun Boat Flotilla to recover two Special Intelligence Service personnel, together with the Norwegian civilians who had been sheltering them, from Batalden island off the west coast of German-occupied Norway in the area to the north of Bergen (28/29 May 1944).

MGB-718 had previously operated from Dartmouth on the coast of south-west England for seven sorties, supporting the French resistance forces with special forces personnel and supplies, across the English Channel to the north coast of Brittany in German-occupied north-western France, and had then operated from Shoreham and Newhaven, on the south coast of England, for a series of seven ferry trips to Dieppe and Ostend, in German-occupied France and Belgium respectively. In the middle of these ferry missions, the boat moved to northern Scotland for two missions in support of the resistance forces in German-occupied Norway. These were 'Cygnus' launched from Lerwick in the Shetlands islands group, and 'Aquarius III' launched from Aberdeen on the east coast of the Scottish mainland.