'Siberien' was a German rendezvous location in the Indian Ocean between Mauritius and Australia where a number of Hilfkreuzer (auxiliary cruiser) surface raiders could meet their supply vessels and replenish their stocks of ammunition, food and fuel as a means of extending their cruises (1939/43).

'Siberien' was used successfully by the raiders Pinguin, Orion, Atlantis and Komet.

Pinguin (known to the Germans as Schiff 33 and HSK 5, and to the British as Raider F) sailed on 22 June 1940 and sent 28 ships (136,551 tons) to the bottom before herself being sunk by the British heavy cruiser Cornwall on 8 May 1941. Orion (Schiff 36, Raider A) departed on 6 April 1940 and sank nine ships (57,774 tons) before returning to base on 21 August 1941. Atlantis (Schiff 16, Raider C) sailed on 31 March 1940) and sank or captured 22 ships (145,697 tons) before being sunk by the British heavy cruiser Devonshire on 22 November 1941. Komet (Schiff 45, Raider B) sailed on 9 July 1940 and, with the aid of Soviet icebreakers, completed a voyage through the North-East Passage to the north of the USSR before debouching through the Bering Strait into the Pacific, sinking six ships (42,959 tons) and then returning to Germany.

The rendezvous was later used for German ships and U-boats transiting between Germany and Japan.

Pinguin was the most successful commerce raider of World War II. Formerly a freighter named Kandelfels, she was built by A. G. Weser in 1936 for the Hansa Line of Bremen with basic data that included a displacement of 17,900 tons, length of 508 ft 6 in (155 m) and speed of 17 kt on the 7,600 hp (5667 kW) offered by two six-cylinder Diesel engines. She was the sister ship of Kybfels, and a half-sister of Goldenfels, which was converted into the raider Atlantis. During the winter of 1939/40 the ship was requisitioned by the German navy and converted into an auxiliary warship by DeSchiMAG of Bremen with a crew of 401, a range of 68,350 miles (110000 km) at 12 kt and a notional endurance of 207 days. Her main armament comprised six elderly 150-mm (5.91-in) L/45 guns removed from the obsolete battleship Schlesien, and she was also fitted with one 75-mm (2.95-in) gun, one twin 37-mm anti-aircraft mounting, four 20-mm anti-aircraft guns, and two single 533-mm (21-in) torpedo tubes for 16 torpedoes. She also carried two Heinkel He 114A floatplanes (later one Arado Ar 196A floatplane) and 300 mines, and also had provision for 25 G7a torpedoes and 80 mines for replenishing U-boats.

Pinguin was one of the first wave of raiders to be despatched, sailing on 15 June 1940 under the command of Fregattenkapitän (later Kapitän) Ernst-Felix Krüder and disguised as an anonymous naval transport ship with an escort from the minesweeper Nautilus. The escort duties were taken over by Sperrbrecher IV on 18 June and later by the torpedo boats Falke and Jaguar. The convoy then sailed through the Great Belt into the Kattegat, passed through the Skagerrak on 19 June with air cover by a Dornier Do 18 flying boat and two fighters, and entered the North Sea. Here the escort was reinforced with the minesweepers M 17 and M 18, and the Germans ships headed to the north along the coast of Norway, passing Bergen, where the torpedo boats departed, on 20 June. Pinguin and the minesweepers proceeded to the Sörgulenfjord, where the grey Pinguin was transformed into a black-hulled Soviet cargo ship, Petschura, with hammer and sickle markings. The ships resumed their passage on the 22 June toward the Denmark Strait.

The first task of Pinguin's mission was to rendezvous with and replenish the U-boat U-A off Cape Verde, and then to disrupt traffic in the Indian Ocean and lay mines off Australian and Indian ports. She was then to head to the south to seek out the British and Norwegian whaling fleets in Antarctica. The German convoy encountered heavy weather and high winds, and the two minesweepers turned back. A surfacing submarine was spotted but, on sighting the pretend Petschura, this disappeared. Assuming the boat was British, Pinguin headed to the north to give the impression of a 'Soviet' ship making for Murmansk. Surfacing again, the submarine increased speed and gave chase signalling first 'What ship?' and on being ignored 'Heave to, or I open fire!'. Pinguin continued at full speed and left the submarine behind, and then continued in a north-easterly direction up the coast of Norway. By 28 June Pinguin had headed to the west, and then turned to the south surrounded by icebergs. She inched southward until 29 June, when she passed through the Denmark Strait into the Atlantic on 1 July to rendezvous with U-A on 18 July. On 10 July she was re-camouflaged as the Greek Kassos. Eight days later, U-A had serious engine problems, and bad weather meant that it was not safe to transfer the torpedoes, water and stores. The raider and the U-boat decided to seek calmer waters to the south, transferring 70 tons of fuel to the submarine en route. On 20 July, in calmer waters 700 miles (1125 km) to the south-west of Cape Verde, they started the replenishment.

This was the first time a U-boat was resupplied at sea by a raider. As the U-boat was unable to come alongside because of the risk of damaging its hydroplanes, the first day was spent improvising methods to close the gap. The 11 torpedoes had to be ferried across on flotation bags, and the task was not completed until 25 July. Pinguin then continued to the south, towing U-A and thus help conserve the U-boat’s fuel. On reaching the shipping lanes off Freetown, Sierra Leone, the U-boat unsuccessfully pursued a tanker. Pinguin then towed the boat again until 28 July. On 31 July, 300 miles (485 km) to the north-west of Ascension island, the raider and a ship spotted each other, the ship turning away and sending a distress signal. Pinguin gave chase and tried to jam the signal, then dropped her camouflage, and ordered the vessel to stop and not to use her radio on pain of being engaged with gunfire. When the commands were ignored a warning shot was fired across her bows by the 75-mm (2.95-in) gun. Four more warning shots failed to halt the flow of distress signals, and the ship’s crew was seen to be manning the stern-mounted gun. Pinguin's main armament then opened fire on the freighter’s bridge and scored several hits. The freighter caught fire and slowed to a halt, and her crew was seen to be abandoning ship.

The 5,358-ton British freighter Domingo de Larrinaga had been steaming from Bahía Blanca to Newcastle with 7,000 tons of grain and a crew of 36. A heavily armed boarding party found eight crewmen dead on the ship. The party included Pinguin's doctor, and two sick bay attendants were sent to care for the wounded. Scuttling charges were placed in the freighter’s engine room, but these failed to explode and the ship had to be sunk with a torpedo after the British survivors had been taken on board Pinguin.

On 20 August Pinguin rounded the Cape of Good Hope and then on 26 August, in the area to the south of Madagascar, launched one of her floatplanes. This located a tanker and the pilot dropped a message onto her deck ordering her to close with the raider and not to use her radio. The tanker appeared to obey this command, but was later found trying to escape at top speed. The floatplane was launched once more, and on finding the tanker ripped away her radio aerials and strafed her bridge with cannon and machine gun fire before alighting and ordering the tanker to show her navigation lights. The tanker was loaded with 10,000 tons of high-octane aviation fuel and 500 tons of oil, and now surrendered and switched on her lights. Pinguin then arrived, and her boarding party identified the vessel as the 6,901-ton Norwegian Filefjell under charter by the British Admiralty and on her way from the Persian Gulf to Cape Town. A prize crew was placed on board the tanker after it had been decided to take Filefjell to a quiet area to transfer the 500 tons of oil to Pinguin.

On 27 August Pinguin's look-outs spotted a ship steaming without navigation lights, and Filefjell was ordered to drop back. Pinguin shadowed the ship for an hour then signalled for her to stop and fired a warning shot across her bows. The ship obeyed and identified herself as the 5,008-ton tanker British Commander. She then radioed distress signals giving her position and reported that she was being attacked by a merchant raider. Pinguin's searchlight spotted that the 4-in (102-mm) gun on the tanker’s stern had been manned and the German captain ordered his own gunners to open fire. The tanker was hit several times and set on fire. The tanker captain stopped his ship and instructed his crew to abandon ship. A torpedo failed to sink the burning tanker, and 40 150-mm (4.91-in) rounds had then to be fired in order to send the ship to the bottom. Pinguin rescued the tanker’s 45-man crew and headed out into the Indian Ocean at full speed.

Later on the same day another freighter was sighted. Pinguin came alongside and signalled that she would be sunk unless she halted. A 75-mm (2.95-in) warning shot was fired across her bows, and the ship then halted with no resistance and no signal sent. The vessel was identified by the boarding party as the 7,616-ton Norwegian Morviken heading for Calcutta from Cape Town. The crew of 35 was taken on board, along with her motor-cutter, then the ship was scuttled.

Pinguin and Filefjell then moved off to the south-east, and thus away from the shipping routes, to transfer the 500 tons of fuel oil, and after this scuttling charges were set on Filefjell . The charges detonated as planned, but the ship did not explode, so 75-mm (2.95-in) rounds were then fired in an effort sink her, but two 150-mm (5.91-in) shells were finally needed to ignite the petrol in the tanks, sending a massive fireball into the sky.

It was now decided that Pinguin should adopt the identity of the Wilhelmsen cargo liner Trafalgar, and the resulting transformation was effected on 31 August, after which the raider drifted until 5 September. The ship then tried to launch its floatplane to survey the area, but the machine crashed on take-off, bursting into flames and sinking, but its crew was recovered from the water. The major loss was the mission’s only radio telephone, which operated on a wavelength undetectable by Allied shipping. Pinguin's technical crew now needed calm weather to assemble the second floatplane, which was crated below deck, and the opportunity was also taken to alter the raider’s appearance once more, and by 10 September the raider had a black hull with a white band all the way around, white upper works and a black funnel with two light blue bands.

The decision was now made to undertake one more sortie off Madagascar before heading for Australian waters to lay mines. Early on 12 September a freighter was spotted 330 miles (530 km) to the east of the island. Pinguin closed fast on a deliberate 'collision course' while the freighter maintained her course in accordance with the international collision regulations until the two ships were just over 1 mile (1.6 km) apart, at which point the freighter sounded a long warning blast of her whistle and turned away from the raider. Pinguin ran up her battle ensign and dropped her concealment as the freighter’s crew manned the ship’s 4-in (102-mm) gun and increased speed. Pinguin signalled the freight to halt fired a 75-mm (2.95-in) warning shot. The freighter fired back, hitting Pinguin with a shell that ricocheted off the surface of the sea and pierced her port side before ending in the crew’s quarters close to the storage compartment containing 300 mines. The shells fired by the 5,872-ton British Benavon had no fuses, however, and therefore did not detonate. One of Pinguin's crew picked up the shell with his cap and threw it into the sea through the hole it had made in the ship’s side. Pinguin fired back, putting the freighter’s gun and radio out of action, destroying most of her lifeboats and setting her on fire. The freighter’s captain gave the order to abandon the sinking ship, but the bridge was then hit and he and his deck officers and the radio operator were killed. A boarding party found five men on board, three of them wounded. They and the 24 others who had abandoned ship were taken on board Pinguin.

Benavon had been on her way to London from Manila and Singapore with a cargo of hemp, jute and rubber, a crew of 49 and the armament of one 4-in (102-mm) gun and one 3-in (76-mm) anti-aircraft gun. Three of the wounded died of their injuries after being brought on board Pinguin.

At this point the raider received orders to set course to the east along the sea route between Australia and South Africa. Four days later, on 16 September, a ship was sighted and stopped without any signals being sent. A boarding party identified the ship as the 4,111-ton Norwegian Nordvard steaming from Fremantle in Western Australia to Port Elizabeth in South Africa with a cargo of 7,500 tons of grain and a crew of 30. A prize crew and more than 10 prisoners were put on board the ship, which was sent to German-occupied France and reached Bordeaux on 22 November.

Pinguin next turned to the north-east in the direction of the Sunda Strait and the shipping lanes between India and Australia. On 27 September the sea was calm enough to allow the spare seaplane to be assembled, and by this time Krüder and his navigator, Leutnant Wilhelm Michaelson, had developed a plan to lay mines in six Australian and Tasmanian sea lanes, even though this would require two ships. On 7 October, off Christmas island, a vessel crossing the raider’s course was ordered to halt, and after a 75-mm (2.95-in) warning shot had been fired, stopped and surrendered. The vessel was identified as the 8,998-ton Norwegian tanker Storstad carrying 12,000 tons of Diesel oil and 500 tons of heavy fuel oil from British North Borneo to Melbourne in Australia. The Germans decided that Storstad could be used as an auxiliary minelayer. A prize crew took Storstad to a remote spot between Java and the north-western tip of Australia for adaptation as an auxiliary minelayer. The tanker was stripped and her after accommodation spaces were transformed into a mine deck with launching rails for 110 mines transferred from Pinguin in the motor cutter taken from Morviken. Some 1,200 tons of the Diesel oil were also transferred from Storstad to Pinguin.

Storstad was commissioned as the auxiliary minelayer Passat under the command of Lieutenant Erich Warning and with a crew of three officers, eight petty officers and 19 ratings plus five members of her original Norwegian crew who had volunteered to work in the engine room. On 12 October Passat headed for the Banks Strait off Tasmania and for the eastern and western ends of the Bass Strait on the approaches to Melbourne. Pinguin headed for the ports of Sydney, Newcastle and Hobart, and also laid mines off the coast of Adelaide. Between 28 October and 7 November the two ships laid their mines and arranged to meet again 700 miles (1125 km) to the west of Perth on 15 November. On 7 November 10,846-ton British refrigerated cargo liner Cambridge hit one of Passat's mines and sank in the eastern approach to the Bass Strait with the loss of one man. On 9 November, at the western end of the strait, the 5,883-ton US freighter City of Rayville hit another of the mines and sank with the loss of only one man. On 5 December mines laid by Pinguin sank the 1,052-ton Australian coaster Nimbin with the loss of seven men. On 7 December another of Pinguin's mines badly damaged Hertford. On 26 March 1941 the 287-ton Australian fishing trawler Millimumul was sunk with the loss of one man.

On 15 November the two German ships made their rendezvous to the west of Perth. Here, on the following day, Passat was decommissioned and resumed her original name. Her German crew was reduced to 18, and 20 Norwegian volunteers supplemented the five already on board. Storstad was now to serve as a scout for Pinguin. The two ships headed in company to the north and then to the west, and on 17 November smoke was sighted on the horizon ahead of a large freighter. Pinguin illuminated the freighter with her searchlight and put a warning shot across her bows, and then signalled the ship to stop and maintain radio silence on pain of being engaged with gunfire. The freighter halted, and a boarding party identified the vessel as the 7,920-ton British Nowshera on her way from Adelaide to Durban and the UK with a cargo of zinc ore, wheat, wool and other assorted goods. The freighter had a crew of 122 men, and was armed with an old Japanese 4-in (102-mm) gun on her stern. Pinguin took whatever goods and provisions she needed, and then scuttled the ship before heading to the south.

On 20 November smoke was again spotted on the horizon, and the raider established that it was from a large westbound cargo ship. Pinguin launched her newly assembled floatplane to snatch the ship’s wireless antennae or if necessary to bomb her. The floatplane failed to snatch the antennae on its first attempt, and its crew then dropped a weighted bag onto the ship’s bridge with a message ordering her captain to stop his ship’s engines and to maintain radio silence or be attacked. Even so, the ship’s radio operator sent signals reporting that the vessel was being attacked from the air, and the floatplane then dropped two small bombs in front of the ship. A second attempt to snatch the antennae then succeeded, but the floatplane came under machine gun and rifle fire, and was hit several times. The floatplane fired back, but was forced down onto the water with a perforated petrol tank and one of its floats damaged. The aircrew crouched down in the cockpit, expecting the freighter’s gunners to finish them off, but Pinguin slowed to half speed and in a risky manoeuvre dropped a boat with a three-man crew beside the seaplane, then pursued the cargo ship. Pinguin opened fire at her 150-mm (4.91-in) guns' maximum effective range: two salvoes were fired, one falling long and the other short, and this was sufficient to persuade the ship’s captain to heave to. A boarding party identified the ship as the 10,123-ton refrigerated transport Maimoa steaming to the UK from Fremantle via Durban with a cargo of 5,000 tons of frozen meat, 1,500 tons of butter, 1,500 tons of grain, 16 million eggs and 100 tons of piece goods. The ship was scuttled and her crew of 87 was taken on board Pinguin which, on the next morning, hoisted in the floatplane.

After Storstad had reported a freighter, Pinguin closed on this and in the dark fixed the ship in her searchlight, fired a warning shot and signalled her to stop and maintain radio silence. The searchlight beam revealed two manned 6-in (152-mm) guns on the freighter’s after deck, so Pinguin opened fire, all the rounds of the first salvo registering hits. The freighter’s radio room was destroyed, the operator being killed, and the bridge was set on fire. The funnel was smashed and the steering gear was jammed, causing the ship to circle. The crew then abandoned their ship, which was identified as the 8,739-ton refrigerated freighter Port Brisbane on her way from Adelaide to the UK via Durban with a cargo of 5,000 tons of frozen meat, butter and cheese, as well as 3,000 tons of wool, lead and piece goods. The ship had a crew of 87, but only 60 men and one female passenger were picked up, the other 27 escaping in a lifeboat during the darkness. Scuttling charges failed to sink Port Brisbane quickly, so a torpedo was fired to finish her.

After failing to find the missing lifeboat, Pinguin headed to the south and then to the west, followed by Storstad. By 28 November Pinguin's appearance had been altered once more by the application of an overall coat of black paint. Two days later Storstad reported a ship on the horizon and departed toward a prearranged rendezvous point. Pinguin closed to within 1 mile (1.6 km) of other ship and opened fire without warning, her first salvo destroying the bridge and radio room, killing the radio operator and mortally wounding the ship’s captain. The steering gear was rendered inoperative, and the burning ship was identified as the 8,303-ton British refrigerated freighter Port Wellington, sister ship of Port Brisbane, bound for the UK from Adelaide via Durban. She was armed with two 6-in (152-mm) guns and one 3-in (76-mm) gun, and was carrying 4,400 tons of frozen meat, butter, eggs and cheese as well as 1,750 tons of steel and 1,200 tons of wheat. She had a crew of 82 and seven passengers. Some 81 of the crew, including the wounded captain, and the seven passengers, all of who were women, were picked up by Pinguin before Port Wellington was scuttled.

From the 11 ships she had sunk by this time, Pinguin now had 405 prisoners on board, and Krüder notified the German naval leadership that he was sending them to Europe on board Storstad, which was still carrying some 12,000 tons of Diesel oil, of which 3,000 tons were transferred to Pinguin before the two ships parted company. It was arranged for three other raiders, Atlantis, Komet and Orion, to be refuelled by Storstad on her way to Europe.

On 8 December Pinguin and Atlantis rendezvoused in the western part of the Indian Ocean, and on the following day Storstad arrived and refuelling began. Pinguin then set course south to intercept the whaling fleets in the Antarctic Ocean to the south of Bouvet island. On 17 December the German naval command signalled that the whaling fleet was to be found in the area around South Georgia and that the names of the Norwegian factory ships involved were the 4,940-ton Harpon, 12,083-ton Pelagos, 12,215-ton Thorshammer, 14,547-ton Vestfold and 12,201-ton Ole Wegger, all under British charter.

On 24 December Pinguin intercepted open-frequency radio chatter between Ole Wegger and Pelagos, and thereby learned that the whaling fleet was awaiting a supply ship, which was overdue, that Pelagos was short of fuel, that Ole Wegger's whale oil tanks were full and that Ole Wegger had offered to transfer some of her surplus fuel to Pelagos. Krüder decided that Pinguin would wait until the two ships were transferring fuel oil, and therefore incapable of manoeuvre, before making any move on them. Another intercepted signal established that the approaching supply ship was the 12,246-ton Norwegian whale oil tanker Solglimt. This attended first to Thorshammer, which was operating 400 miles (645 km) to the south-west, and then on 13 January tied up alongside Ole Wegger. On the next day, as the two ships lay side-by-side, Pinguin approached from the west, slipped alongside Solglimt, ordered the two ships to maintain radio silence, and boarded each ship with a prize crew. Solglimt had 4,000 tons of whale oil and 4,000 tons of fuel, and was manned by a crew of 60, while Ole Wegger had 7,000 tons of whale oil and 5,500 tons of fuel, and was manned by a crew of 190. Both ships were captured within 45 minutes. The Norwegian captains were told to continue with their whaling and that the Reich would pay them for their work.

Pinguin then despatched a motor boat to round up the whale catchers associated with the factory ships. Three of these managed to escape, but the other four, the 247-ton Torlyn, 293-ton Pol VIII, 354-ton Pol IX and 354-ton Pol X, were captured without incident. In order to confuse the Norwegians, Pinguin sailed in the direction opposite to that in which the third factory ship was operating. Once out of sight, the raider turned and approached the brightly lit vessel in dense fog. Coming at full speed to within 220 yards (200 m), Pinguin signalled warnings and despatched prize crews, and Pelagos was captured within minutes. The ship was carrying 9,500 tons of whale oil and 800 tons of fuel, and was manned by a crew of 210. The ship’s captain was ordered to recall his catchers, which were all operating nearby. These were the 247-ton Star XIV, 249-ton Star XIX, 249-ton Star XX, 298-ton Star XXI, 303-ton Star XXII, 357-ton Star XXIII and 361-ton Star XXIV, all of which were seized.

Pinguin's foray against the Norwegian whaling fleet was the single most successful performance by a German auxiliary cruiser during World War II inasmuch as more than 36,000 tons of shipping, a supply ship, two factory ships, 11 whale catchers, 20,000 tons of whale oil and 10,000 tons of fuel oil were captured, all without a single shot being fired and without any casualties.

Pinguin then made a five-day dash at top speed to the north-west past Bouvet island and more than half-way to the South Sandwich islands group in order that she could send a long coded radio message home in the knowledge that every wireless station in the region would detect the transmission and fix the position of the sender. Pinguin then sailed back to the captured Norwegian fleet, her radio equipment intercepting a number of British signals confirming the success of the ploy.

The 15 ships then set off to the east with Pinguin in the lead and the supply ship and two factory ships at the rear. So great was her bag, it should be noted, that Pinguin could not provide prize crews for all of the ships. Ole Wegger transferred 7,000 tons of whale oil to Solglimt's storage tanks. Solglimt and Pelagos then departed on 25 January with their 10,000 tons of whale oil to German-occupied France, Pelagos reaching Bordeaux on 11 March and Solglimt on 16 March.

The German naval leadership ordered Pinguin to bring Ole Wegger and all 11 whale catchers to the mid-Atlantic 'Andalusien' rendezvous point to the north of the island of Tristan da Cunha to meet the oiler Nordmark, which carried prize crews for the remaining whalers. Pinguin and Nordmark, the latter towing the refrigerator ship Herzogin (ex-British Duquesa), met on 15 February. On 18 February the supply ship Alstertor also arrived at the rendezvous with a fresh supply of torpedoes, mines, a crated Ar 196 floatplane and mail for Pinguin's crew. The German ships then proceeded with the whaling ships to the Kerguelen islands group, where the replenishment could take place in safety. Herzogin had run out of everything that could be burned to keep her refrigeration plant working: her entire bridge structure, lifeboat derricks, masts and all teak decking had been burned, and she would have to be sunk. Pinguin was restocked with 360,000 eggs, 47 sides of beef, 410 sheep carcasses and 17 sacks of oxtails before the scuttling charges were set on Herzogin. Ole Wegger and 10 of the catchers also arrived at the rendezvous, where they were manned by skeleton prize crews before departing for Europe. The newest of the catchers, Pol IX was retained as an auxiliary minelayer Adjutant.

Star XIX and Star XXIV were stopped by the British sloop Scarborough off Cape Finisterre on 13 March, the German crews scuttling their prizes and and being recovered by the British. Ole Wegger and the other eight catchers reached Bordeaux on 20 March.

Pinguin was next ordered to rendezvous with the raider Kormoran in an area to the south of St Helena island on 25 February to deliver 463 lb (210 kg) of the white metal WM80 needed by Kormoran to manufacture replacement bearings for her engines. Pinguin then headed to the south past Prince Edward and Crozet islands, and rendezvoused with another raider, Komet, 120 miles (195 km) to the east of the Kerguelen islands group on 12 March. Adjutant was sent ahead to take soundings at the entrances to the various bays and inlets of the islands so that Pinguin could avoid any rocks, and Pinguin followed Adjutant into Gazelle Bay, the sheltered natural harbour at Port Couvreux, and rafted up alongside her on 13 March. Komet departed on 14 March. Pinguin's replenishment then began, and one of the first items to be hoisted out of Alstertor's holds was the Ar 196 floatplane. It was here that Adjutant was converted into an auxiliary minelayer for her role in mining the approaches to the port of Karachi. Pinguin was also careened so that her lower hull could be scraped and cleaned. The new floatplane was assembled and the ship’s appearance was changed to that of the Norwegian liner Tamerlane. Pinguin also replenished her water supply from a waterfall. By 22 March the replenishment from Alstertor was complete, and Pinguin and Adjutant departed the islands on 25 March on a course to the north-east and a meeting at the 'Siberien' rendezvous point with a former Norwegian tanker and a supply ship, unaware that these had both been sunk.

Pinguin and Adjutant spent a short time cruising the area of the Saya de Malha Bank before heading to the north, and spent the next three weeks searching to the north and south of the Seychelles islands group. In this time Pinguin's floatplane made 35 fruitless flights in search of any tanker that would be suitable for adaptation as an auxiliary minelayer. On 24 April Adjutant was searching farther to the north, off the island of Mahé, when she came across a large freighter and reported its course and speed to Pinguin. On the following day Pinguin steamed past Adjutant at full speed and opened fire, shooting away the freighter’s radio antennae, crippling her steering gear with the first salvo, and bringing her to a halt. Pinguin dispatched a boarding party which identified the vessel as the 6,828-ton British freighter Empire Light on her way from Madras to Durban with a cargo of ore, hides and piece goods, and manned by a crew of 70. The ship’s steering had been so badly damaged that it could not be repaired, so the ship was scuttled with explosive charges.

On 27 April Pinguin's floatplane sighted a ship, and the raider chased this ship for five hours until another freighter was spotted, whereupon Pinguin changed the object of her chase. The raider opened fire on the freighter at a range of 5,470 yards (5000 m) on the following morning, destroying freighter’s radio room and steering gear. The second salvo blew the freighter’s 4.7-in (119-mm) gun into the engine room, and the freighter was then abandoned by her 110-man crew after distress signals had been transmitted from an auxiliary radio, but these were weak. The freighter was identified as the 7,266-ton British Clan Buchanan on her way from the USA to Madras with a cargo of military equipment. The Germans then scuttled the ship.

Pinguin next altered course toward the shipping routes between the Persian Gulf and Mozambique, Adjutant being instructed to head to Point Violet in the event of Allied naval activity. Clan Buchanan's weak signals had in fact been picked up by two stations, and powerful naval forces were mobilised on each side of the Indian Ocean.

Pinguin was searching for a tanker in the north-western part of the Indian Ocean near the entrance of the Persian Gulf when, on 7 May, she sighted a small tanker. The raider signalled the tanker to heave to, but she refused to obey, and her radio operator transmitted distress signals describing their attacker and identifying herself as the tanker British Emperor. Pinguin's gunners fired a salvo of deliberate near misses in an effort to persuade the 3,663-ton British Emperor to stop, but the tanker held her course and continued sending distress messages. Pinguin then fired a salvo which destroyed the tanker’s bridge and wheelhouse, and British Emperor veered off course and started to go steam in circles trailing dense black smoke as her cargo ignited, before coming to a halt. The men of the tanker’s crew were seen jumping overboard and Pinguin sent boats to pick them up. While Pinguin's rescue party was alongside British Emperor, more distress signals were detected, and after the rescue boats had moved away from the blazing tanker the raider’s guns opened fire once more, tearing away the bridge structure and silencing the signals. A torpedo was fired to sink British Emperor as quickly as possible, but the weapon began to circle, requiring Pinguin to turn sharply to starboard. The torpedo passed just 220 yards (200 m) ahead of the raider. A second torpedo missed the tanker, but the third hit her square amidships, sinking her.

Pinguin departed to the south-east. British Emperor's SOS signals had been detected as far away as Germany, and were also detected by the British heavy cruiser Cornwall some 500 miles (805 km) to the south of Pinguin. The cruiser immediately altered course to the north on the assumption that Pinguin would probably be heading to the south, as was indeed the case. On 8 May Pinguin spotted the silhouette of a British warship on the horizon, and immediately altered course away from her at maximum speed in a south-westerly direction. One of Cornwall's Supermarine Walrus flying boats was searching the area and spotted the disguised Pinguin, but was anxious not to attack a possibly innocent ship. Four hours later the Walrus returned and circled Pinguin, which the aircrew believed to be a typical Norwegian freighter. Pinguin was flying the Norwegian ensign and had the name Tamerlane displayed on both sides of her bridge. At this time Cornwall was just 65 miles (105 km) distant from Pinguin, the members of whose crew were wearing typical merchant marine clothing. The Walrus returned 90 minutes later and requested the ship’s identity, cargo and port of destination. The silhouette outline of the Tamerlane shown in the shipping register matched what the Walrus’s observer had seen. Tamerlane was not among the names on the list of merchant ships known to be in the area at that time, however, and the crew of the Walrus was therefore suspicious.

Cornwall headed to the south-west at maximum speed and launched another flying boat. The raider’s look-outs spotted Cornwall as she approached at high speed, and Pinguin's crew went to action stations, although the guns still remained concealed as she was still depending on her disguise as long as she could. Pinguin transmitted raider reports, identifying herself as Tamerlane and claiming that she was being attacked by a German warship. Cornwall's radio operator heard these signals and reported that they were being sent on a British merchant navy transmitter. Cornwall radioed the circling Walrus to inform the supposed Norwegians that the ship bearing down on them was British and order them to heave to, and Pinguin then adopted the classic defensive response of presenting her stern. Cornwall closed to within 22,000 yards (20115 m) and signalled Pinguin three times by lamp with instructions to heave to on penalty of being engaged by gunfire. A warning shot was fired from one of Cornwall's 8-in (203-mm) guns high and to port of Pinguin, then the warning signals were repeated and another warning shot was fired.

Cornwall's second Walrus was prepared for launch with two 250-lb (113-kg) bombs, and ordered to drop the first bomb in front of the fleeing Pinguin; if that failed to halt her the second bomb was to be dropped on her forecastle. Meanwhile Cornwall closed to 13,000 yards (11900 m). At 17.14 on 8 May, with the two ships 8,750 yards (8000 m) apart, Pinguin dropped her disguise, ran up her battle ensign, turned sharply to port to bring her full broadside to bear, and opened fire with five guns simultaneously, straddling Cornwall. The cruiser suffered a failure in the electrical circuit which controlled the training of her main gun turrets, and therefore broke off and began to retire out of range to effect repairs. Cornwall also suffered a complete breakdown in the telephone link between the bridge and the guns and the line to the aircraft catapult. An officer was dispatched aft to order the waiting Walrus to bomb Pinguin, but the Walrus had suffered splinter damage and was unable to take off.

Pinguin had registered her first direct hit, putting Cornwall's engine room telegraph out of action and severing crucial wiring in her steering system. Cornwall was temporarily out of control, and another hit started a small fire. Out of range of Pinguin's guns, the damage to the cruiser’s turret circuits was repaired. The first Walrus was now spotting for Cornwall's guns, which soon started to straddle Pinguin and then registered a first hit, which brought down the foremast. Krüder now ordered the release of the prisoners, the setting of the scuttling charges and the abandonment of the ship. At that very moment a four-gun salvo from Cornwall's 8-in (203-mm) forward turrets destroyed Pinguin. The first shell struck the foredeck, destroying the two 150-mm (5.91-in) guns located there. The second shell hit the meteorological office and shattered the bridge, killing Krüder and all but one other man. The third shell devastated the engine room. The fourth shell exploded in hold number five, detonating the 130 mines stored there and ripping the raider’s after part to pieces. Flame rose thousands of feet into the air, and fragments of the raider were scattered across the surface of the sea. Pinguin was gone within five seconds.

The action had lasted just 27 minutes, and in this time Pinguin had fired more than 200 rounds at Cornwall, which had fired 136 rounds. The cruiser’s boats picked up 61 members of Pinguin's crew and 24 of her former prisoners. Of the 401 Germans on board Pinguin, only three officers, one prize officer and 57 petty officers and men survived. Of the 238 prisoners on the Pinguin only nine officers and 15 seamen survived. Thus 214 prisoners and 341 of Pinguin's crew were lost. In her raiding career, Pinguin had sailed more than 59,000 miles (94950 km) in 357 days, had sunk or captured 28 ships, a total of 136,642 gross registered tons. Of this last, 52,000 tons had been sent back to Germany as prizes. Pinguin's mines had sunk another four ships totalling 18,068 tons. Pinguin's total sinkings therefore amounted to 154,710 tons.