Buenos Aires was built in 1911. It was a large ship with three decks and a crew of over 100 men.

On May 2, 1940, the British submarine HMS Narwhal discovered a German convoy heading north towards Norway with soldiers, military equipment, and horses. It sank the transport ship Buenos Aires with 6 torpedoes. At 2245, the ship sank after the Germans attempted to tow it towards Frederikshavn. The transport ship Bahia Castillo, with a gross tonnage of 8579, which was also part of the convoy, was severely damaged during the torpedo attack but never sank; instead, it was towed to Frederikshavn by the Germans. The sinking of Buenos Aires was clearly visible from the islands on the west coast. From places like Rörö and Marstrand, it was reported that the gunfire was so intense that the window panes rattled.

The cargo holds contained motorcycles, cars, weapons, horse skeletons, and various military equipment.

In 1953, according to the newspaper Skagens Avis, two cars were salvaged from the wreck. Many rumors are circulating that several hundred soldiers went down with the ship, but given that there was plenty of time, three hours, before the ship sank, this is not likely. The brass propeller weighing 35 tons was salvaged from the wreck in 1953.