Even today just how the vessel was acquired by Iceland remains a mystery. Although it is an American design the official position of the United States has always been that they did not provide the vessel to Iceland. The Gato-class was widely exported during the Second World War and therefore there were numerous potential sources from whom Iceland could have acquired it but even the Iceland government have neither confirmed or denied the vessel's existence. It was a true mystery.
The Ullr itself was one of the Gato-class of conventionally powered submarines produced in the United States before and during the Second World War. By 1975 it had been obsolete for quite some time and was no match for the highly sophisticated anti-submarine force of the Royal Navy. Nevertheless the vessel managed to sneak its way to Iceland to begin operations around the country. Many now believe it was transported through Royal Navy and NATO patrol routes aboard a cargo ship rather than transported there under its own power.
The Ullr is suspected to have begun operations on the night of September 13th 1974. It was on this date that the last message from the Belgain trawler Le San was heard by a Royal Air Force Shorts Singapore MR.2 patrol aircraft. It disappeared shortly after and debris found later led Belgian authorities to believe the vessel had suffered an explosion. It was probably destroyed by the Ullr's deck guns as this was the preferred method of sinking fishing vessels.
The Ullr is suspected to have ventured out to sea again on December 3rd 1974 when the British fishing trawler Norton Warrior disappeared without trace. Another British trawler disappeared five days later prompting the British government to increase its air patrols in the region (at the time it was simply believed that foul weather was to blame and the additional patrols were intended to speed up rescue efforts).
The Cod War and SinkingEdit
When the Cod War began the Ullr disappeared in the face of Royal Navy warships swarming the North Sea until
January 1976 when things were turning against the Icelandics. What began as a fishing dispute was about to get very bloody as the vessel ventured out into the disputed region. RAF patrols spotted a submarine believed to be the Ullr on the surface on January 7th and was initailly thought to be Russian. A few hours later a distress call was sent from the trawler Northwind and an RAF Singapore MR.2 went to investigate spotting the Ullr diving after shelling the Northwind.
Armed British maritime patrol aircraft were launched and spotted the submarine a few hours later trying to hide along the Icelandic coast. Although it was in Icelandic territorial waters the British aircraft were ordered to sink the submarine. An air launched torpedo from a Nimrod struck the submarine breaking it in half. There were no survivors.
As can be expected the theories about the vessel are rampant and varied but the most likely is that the vessel was provided (and perhaps crewed) by the CIA hoping to stir up trouble to distract Britain from international affairs. The main question that accompanies this theory was whether or not the Icelandic government knew about the vessel. Some believe that rogue elements of the Icelandic Coast Guard worked with the CIA to provide support for the vessel.