Don your Sherlock Holmes hat for this unsolved mystery: A MADMAN’S FINAL REVENGE, or how New York City was saved by a Uboat mutiny.

On 10 July 1945, a German submarine, U-530, a Type IXC/40 boat, appeared in the Argentine port of Plata del Mar and surrendered to the Armada de la República Argentina, an officially belligerent but Nazi-sympathetic navy, more than two months after the formal surrender of Nazi Germany and the direct order of Admiral Karl Dönitz to all u-boats at sea to surface and immediately surrender to the nearest Allied authority.

Not only were the actions of U-530’s commander a direct contravention of the surrender terms formalized on 8 May 1945 between the Allied Powers and the German government and military, but the circumstances of the last voyage of the U-530 were also very mysterious, and remain so to this day. When taken over by the Argentines, U-530 was completely devoid of ships papers — the logbook, manifest, written orders, dockyard papers, etc. The personal identity documents of the crew, their soldbuchs and ID disks, were also missing. There was virtually nothing on board to account for the movements and mission of the vessel since leaving Horten Naval Base in Norway shortly before the war ended except for the personal testimony of the commander and his crew, and they weren’t very talkative.

When asked to explain why he had not followed Admiral Dönitz’s surrender directives, Oberleutnant zur See Otto Wermuth, would only say he was under orders “from Berlin”, which could only mean direct orders from Hitler himself, since in the German submarine service in WWII there was no one with higher authority than Dönitz except Hitler as commander-in-chief of the Wehrmacht.

The condition of the submarine itself was highly suspicious. The casing (the outer superstructure built over the pressure hull) and the conning tower were extremely rusty, and much of the paint was missing, having been either scraped or burned off. Her 10.5cm SK C/32 deck gun and mount were missing along with its ammunition, apparently having been jettisoned at sea. Also, there were no torpedoes or torpedo racks in her torpedo spaces fore and aft. No explanation of the vessel’s condition was offered by Wermuth or his subordinates.

After the sub and its crew were turned over to the Americans, the crew were further interrogated by ONI officers, but nothing more was learned (or more precisely, nothing more was learned that was published.) Wermuth and his men were eventually released and repatriated to Germany, because the only viable war crime charge that could be preferred against Wermuth or the crew, the postwar sinking of the Brazilian cruiser Bahia on 4 July 1945, was shown to be false. The submarine itself was sunk as a torpedo training target by USS Toro on 28 November 1947.

There are many theories offered to explain the voyage of the U-530. The most outlandish ones suggest that the sub was transporting high-ranking Nazi military and political figures, perhaps even Adolf Hitler and Eva Braun themselves, to a secret landing somewhere on the coast of Argentina or Uruguay. These speculations account for the large empty spaces fore and aft (i.e. accommodation for passengers) and her surrender to Argentina but do not account for the delay. U-530 was a schnorkel-equipped vessel and could have sustained 6 knots submerged all the way from Norway, about 48 days. U-530 was at sea 63 days after the surrender.

Another theory is both more plausible and more sinister. There is reason to believe that after the firebombing of Dresden (‎13–15 February 1945) Hitler ordered a revenge attack on the United States in the form of a nerve gas assault on New York City by submarine. By 1945 Germany had invented and stockpiled at least two nerve agents able to be deployed by explosive ordnance, Sarin and Tabun, which could have been made into shells capable of being fired by U-530’s 10.5cm deck gun. Surfacing at night in the East River would have made a catastrophic nerve gas bombardment of Manhatten and Brooklyn possible, but almost certainly suicidal. Hitler was talked out of this gas attack by his most trusted underlings, including Albert Speer, as self-defeating because it would give the Americans a justification of using its chemical warfare agents on Germany or so says the tale. However, it may be that Hitler resurrected his submarine-launched gas attack plan as a final gesture of defiance.

The gas attack on NYC theory explains much of the known facts about U-530’s last patrol. First, there is the absence of torpedoes and torpedo racks. Both the forward and after torpedo rooms had watertight (and therefore airtight) interior hatches and torpedo loading hatches leading to the weather deck. Without torpedos or torpedo racks these spaces could be used as chemical ammunitions handling rooms for the deck mount that would not endanger the rest of the crew spaces should there be an accident.

Secondly, it explains the absence of ship and crew documents. Wermuth and his men would rightly fear prosecution for war crimes if their participation in a gas attack scheme were ever exposed.

Thirdly, the poor physical condition of the boat can be explained as a consequence of a mutiny aboard U-530. Consider the following scenario: After putting to sea under sealed orders and having been supplied with a huge load of “special” shells for the deck gun in lieu of torpedoes, the crew discovers the true nature of their mission. Not wanting to be hanged by the Allies or to give the Americans an excuse to attack Germany in kind they hatch a mutiny plot. While running on the surface the lookouts seize Oblt.z.S. Wermuth or his first officer. They also gain control of the conning tower and foredeck hatches to prevent U-530 submerging to drown the mutineers. After gaining at least partial control of the boat the mutinous crewmen proceed to foil the gas attack plot by detaching the deck mount and throwing it overboard. Further suppose, that while laboring to jettison the deck gun or fighting with loyal crew members the mutineers somehow set fire to the weather deck, which burns off the much of the paint. This would explain the severely rusted appearance of U-530’supperworks.

With his deck gun jettisoned, Wermuth has no means to use the deadly shells stored in the torpedos spaces. Consequently, he agrees to the mutineers’ demands: He must take the u-boat to some deserted stretch of deep water where the nerve gas shells can be safely thrown overboard without significant risk of encountering a witness. Next, he must agree to destroy all documents that could be used to link the ship and its crew to the gas attack plot.

To dispose of their deadly cargo there could hardly be a better spot than the Scotia Sea.

In June and July 1945 the Scotia Sea was among the most deserted waters on the planet. June and July are winter months in the Southern Hemisphere, and in the 1940s much of the ship traffic in the Scotia Sea consisted of fishing and whaling vessels. In winter the whales are gone, and the sea is generally too rough for fishing assuming there is much fish to catch. Furthermore, the waters there are very deep — 19,000 feet and more. In other words, perfect for the mutineers’ purpose. This putative voyage to the Scotia Sea accounts fairly well for the 63 days delay in surrendering.

Addenda

1. Soldbuch (literally pay book). When a young German presented himself for active duty, he received an Erkennungsmarke (dog tag) and a Soldbuch, which was the basic identity document that the soldier or sailor would carry on his person for the rest of his active military career. The title “pay book” is somewhat misleading, because little or no pay is actually recorded in the document. Instead, the book gave the serviceman the authority to draw pay, and in fact, the original intent of the document was to allow individuals to draw pay from a unit other than their own. In practice, the Soldbuch was the identity document that most concerned active duty personnel. Inside its tan leather cover, the 24 pages contained an array of information that included the serviceman’s current and past assigned units (former units were crossed out but legible), pay rate, awards, equipment/weapons issued, clothing, Erkennungsmarke number, and some medical history.
2. On the matter of Argentine and Urugyuan belligerence in WWII.Both countries had, and have to this day, a large German-speaking population who often celebrated their Germanic culture and expressed sympathy for Germany during the war. Both nations tried to maintain a neutral stance during the whole course of the conflict and failed. Under economic and political pressure from the United States, both Argentina and Uruguay declared war on the Axis powers, Uruguay in February 1945 and Argentina about five weeks later.
3. The sinking of cruiser Bahia. U-530 was suspected of having destroyed the Bahia because the u-boat could have been nearby when the Brazilian warship sank on 4 July 1945. However, survivor testimony revealed that the sinking was accidental. Bahia was scheduled to escort aircraft supply ships to the Pacific. In preparation for deployment to areas where Japanese attacks could occur Bahia’s crew drilled with her AA suite by firing at a kite. One of the anti-aircraft guns aimed too low and hit one or more depth charges on the stern racks. The resultant explosion tore the stern off Bahia, which sank in three minutes.
4. Sailing time to Argentina. My estimate of 48 days assumes a steady pace of six knots, which is about the maximum sustained speed of Type IX boat using a schnorkel. However, the actual speed would likely be faster. Though the schnorkel allowed the diesel motors to operate while submerged there was still a need to surface every two days to ventilate the breathing air which would otherwise be polluted with toxic levels of CO₂ and CO. During those ventilation runs the boat could dash ahead at her best speed of about 18 knots. U-530 was equipped with the FuMO 61 Hohentwiel radar transmitter and theFuMB 26 Tunis radar detection system. Using these sensors the vessel could operate on the surface at night with greater safety than most u-boats. Maintaining an average speed of 8 knots U-530 could reach the Scotia Sea and return as far as Plata del Mar in almost exactly 63 days.