Kattegat was one of two naval tankers the Germans intended to use in order to quickly refuel the ten destroyers of the Narvik task force, enabling them to escape back to Germany before the Royal Navy could trap and sink them.

[11] The Kriegsmarine support tanker had sailed to Norway from Wilhelmshaven on the German North Sea coast on 3 April in preparation for the invasion.

[12] While the other tanker, the 11,766-ton whale oil factory ship Jan Wellem, had reached Narvik from the German Basis Nord at the Bolshaya Zapadnaya Litsa inlet on the Kola Peninsula in Russia before the German attack,[10][13][14] the captain of Kattegat had been warned of a British naval mine field in the Vestfjorden (Operation Wilfred) and refused to continue, choosing instead to anchor up in Sandlågbukta, Neverdal at Ørnes in Meløy Municipality.

[10] After closing to a cable length of Kattegat, Lieutenant Commander Seip hailed the German tanker, demanding that it identified itself.

Naval District to take her as a prize, but after speaking with two Norwegian pilots who had guided the German tanker a short time earlier he decided that this would be too hazardous an undertaking.

Thirty-four of the crew were brought on board Nordkapp as PoWs from a nearby wharf, while the remaining five managed to escape into the hills after their ship was sunk.

[16][19] As the five-destroyer-strong 2nd Destroyer Flotilla under Commodore Bernard Warburton-Lee entered the Ofotfjord on 10 April to initiate the First Battle of Narvik, Vice Admiral William Whitworth, in charge of the Royal Navy forces in the Narvik area, received a message from Norway stating that Kattegat had been intercepted and sunk 3 nautical miles (5.56 km) off shore.

[22] From 16 to 22 April Nordkapp was deployed with a Royal Navy squadron of 14 warships and two troopships that had arrived at Sjonafjord north of Sandnessjøen.

During the time she followed the British vessels, the force was subjected to several German air attacks without the Norwegian ship suffering any damage.

[22] On 7 June 1940 Nordkapp arrived at Svolvær and received the order that had been given by the Norwegian High Command to evacuate all operational naval vessels to allied ports.

[24] After the nearly fatal friendly fire incident, Nordkapp returned to Svolvær and took on board volunteers before leaving port at 0300hrs on 8 June.

[31] On 11 September 1944 she sailed from Portland to Aberdeen for maintenance and stayed there until 15 December 1944 when she was again transferred,[32] this time to guard duties at the Home Fleet's main base at Scapa Flow, a role she would continue until 1 January 1945.

[2] On 18 May 1945, ten days after the final German surrender in Norway, Nordkapp left her exile in Methil in the United Kingdom and sailed for home.

[32] After the end of the Second World War Nordkapp resumed her pre-war duties as a coast guard vessel until being decommissioned and laid up in Horten on 29 July 1954.

Her long career ended on 27 November 1972, when she sank off West Africa after suffering leaks and disastrous hull failure.