In 1960, the Argentinean Navy tracked 2 unidentified submerged objects in the Golfo Nuevo, 650 miles south of Buenos Aires. At first it was thought that they were US submarines, but then they appeared to break apart and fly out of the water. On each occasion an unidentified submarine was hunted by up to 14 Argentine warships, including an aircraft carrier, as well as over 30 navy planes. The submarines, though audible and occasionally visible to the naked eye, could not be triangulated by sonar, sonar buoys, hydrophones, or radar. Despite intense bombing and depth charging by the most up to date US explosives, torpedoes & naval gunfire, it proved impossible to damage or sink the submarines, and the hunt was abandoned on each occasion without success.
At the time, Nikita Khrushchev, was so impressed with the report that he ordered his representative in Buenos Aires to find out more about the event. Skeptics suggest that what was seen, were submarines firing torpedoes, but it has been noted that in 1960, the firing of 6 or more torpedoes simultaneously was not possible.
Capt. Ray M Pitts, the leader of the U.S. Navy anti-submarine warfare team involved in the 3rd hunt, confirmed afterwards that it had been a definite submarine, but he was prevented from saying more. Some sailors and eyewitnesses described it as a Type XXI U-boat developed by the German Navy 15 years earlier.