German auxiliary cruiser Komet

After a long period of negotiations between Nazi Germany and the Soviet Union, the Soviets agreed to provide Germany with access to the Northern Sea Route through which Germany could access the Pacific ocean.[3] Although the two countries had signed the Molotov–Ribbentrop Pact (with secret protocols dividing Eastern Europe) and an undisclosed commercial agreement (extensive military and civilian aid pact), the Soviet Union still wished to maintain the veneer of being neutral, and secrecy thus was required.[3] Initially, the two countries had agreed to send 26 ships, including four armed merchant cruisers, but because of a variety of difficulties, this was soon reduced to just one vessel, the Komet,[3] the smallest one of the units that Germany wanted to use as auxiliary raiders.[4]

Prior to being sent on the Northern Sea Route, the Komet was equipped with a specially strengthened bow and a propeller suitable for navigating through ice.[5] Under the command of Kapitän zur See (later Konteradmiral) Robert Eyssen, HSK7 departed for her first raiding voyage from Gotenhafen (now Gdynia in Poland), on 3 July 1940 with a crew of 270.[5] The ship stopped in Bergen on 9 July to refuel and resupply.[6] Then she started again her route towards the Arctic Ocean.

With the consent of the then supposedly neutral Soviet Union, Komet initially made her way along the Norwegian coast disguised as the Soviet icebreaker Semyon Dezhnev.[5] While waiting in Teriberka Bay in July and August because of Soviet security concerns, she took the fake name the Donau.[5] With assistance from the Soviet icebreaker Lenin, she passed through the several Arctic Ocean passages in August.[7] She also later received help from the Joseph Stalin.[7] In early September, the Komet crossed the Bering Strait into the Pacific Ocean.[7]

Komet disguised as the Manyo Maru

The passage was an amazing achievement and would have ended in disaster had it not been for the Soviets, whose help had come at a price: 950,000 Reichsmarks.[7] For many of the German crew, this was their first experience in Arctic waters.[8]

Movements of the three German ships in December 1940 and January 1941

Once in the Pacific, Eyssen sailed down to the Japanese island of Lamutrik and met the Orion and Kulmerland in mid-October. After a conference on strategy, the three captains decided to work together, concentrating on the New Zealand to Panama passage taken by most of the Allied merchant ships. They decided on Japanese disguises – Komet and Kulmerland had the names Manyo Maru and Tokio Maru painted on their hulls.

In early November, Komet resupplied and refueled in Japan, disguised as the Japanese merchantman Manio Maru.[9] She operated with the Orion, disguised as Mayebashi Maru and the supply ship Kulmerland, posing as the Tokio Maru.

Together with the other two ships, on 25 November she sunk the coaster Holmwood[1] and two days later, when 300 miles east of New Zealand, the passenger liner Rangitane, raiding her precious food load.[10] By that time, Komet had already been at sea for 140 days and Eyssen admitted in his war diary that he had become depressed and frustrated at not having encountered the enemy.[11]

During December, Komet and Orion casually[12] met and sunk in the waters surrounding Nauru Island five Allied merchant ships, with a combined tonnage of about 41,000 tons, that had been waiting off the island to load phosphate (of which Komet sank three).[13][14] Between 6 and 7 December the Komet sunk the merchant ships Triona, Vinni and Komata,[15] taking more than 500 prisoners, that were landed a few days after on Emirau Island.[16]

At the end of December Eyssen planned to lay a minefield at the entrance of the Rabaul's harbour. He was forced to abandon his plan due to an engine failure on the Meteorit boat that was designed for the mission.[1] He, therefore, decided to set course towards Nauru, wanting to land his troops and occupy the phosphate processing and loading facilities on the island. The bad weather though convinced Eyssen to change his plans into a direct attack to the island infrastructures.[16]

On 27 December 1940 the Komet sent a warning to the island and announced that the attack was about to begin. She shelled and heavily damaged the loading plants and mooring buoys of the port. The bombing lasted an hour, and it caused the loss of 13,000 tons of oil.[16] The Nauru phosphate extraction facilities did not resume their pre-war output levels until the end of the conflict.[17] The action also led to the promotion of Eyssen to Konteradmiral on 1 January 1941.[18]

After the Nauru attack (probably the major German success in the pacific operational area during the war) the Komet received the order to set a new course towards south, crossing the Indian Ocean and scouting the presence of Allied whalers.[19] After a few months with no success, the ship reached the shores of Antarctica on 16 February 1941; later on 6 March she had a stop on the French Kerguelen Islands[20] and had there a brief meeting with the other German auxiliary ship Pinguin.

The hunt for allied ships in the Indian Ocean had no success; after some months, Eyssen sailed towards the Panama Canal, hoping to find more convoys in the Pan-American Security Zone, recently opened to military actions from the Kriegsmarine high command. From 14 July 1941 until 25 July the Komet was resupplied by the German freighter Anneliese Essberger near the Tuamotu Archipelago.[21] At this time, the Komet was disguised as the Osaka Shosen Kaisha line Ryoku Maru.

On 14 August the ship met near the Galápagos Islands the British freighter Australind and sunk it.[22][23] Three days later the German cruiser met the Dutch 7,300 ton freighter Kota Nopan, loading more than 2,000 tons of tin and manganese.[24] Due to her precious load, the supply ship was spared from sinking and captured. On 19 August Komet met the freighter Devon and sank it.[1] Except for some casualties, the German sailors saved the crew members of the enemy ships, that became prisoners of war.[25]

After these three successes, Eyssen decided to move out of the area, fearful of the reaction of the Allied navy. Komet headed towards New Zealand accompanied by the captured Kota Nopan. At the end of September she had a brief meeting with the auxiliary cruiser Atlantis[26] and transferred to her a part of the prisoners and cargo load[27]

Komet then received the order to return to Germany. The ship set a new course towards Cape Horn, sailing at a slower speed in the Atlantic Ocean disguised as the Portuguese freighter S. Thomé.[2] The captured Kopa Notan was sent as a prize to Bordeaux, in occupied France, arriving there on 17 November. Komet reached the French port of Cherbourg on 26 November,[1] disguised as the freighter Sperrbrecher 52. The day after she had a short stop in Le Havre and then sailed towards Germany. Some British torpedo bombers spotted her in the English Channel but were not able to sink her. After having landed all her prisoners of war at Cuxhaven,[1] the auxiliary cruiser finally reached Hamburg on 30 November 1941[28] after a voyage of 516 days and about 100,000 nautical miles (190,000 km). The ship had sunk seven ships (two in conjunction with the raider Orion) for a total of 41,568 tons.[1]