German submarine U - 507 German submarine " U - 507 " was a Type IXC U - boat of the Nazi German " Kriegsmarine " built for service in the Second World War and the Battle of the Atlantic . She was mainly notable for two patrols she conducted during the " Second Happy Time " in mid - 1942 , during the first of which she caused havoc in the Gulf of Mexico amongst unprotected American shipping , and then in the second she attacked ships along the coast of Brazil , in an inexplicable and shocking attack on a neutral nation ' s shipping in its own waters which almost single - handedly provoked the Brazilian declaration of war on Germany . The U - boat was built during 1941 by the Deutsche Werft shipyards in Hamburg , and commissioned on 8 October 1941 , with " Korvettenkapitän " Harro Schacht in command . Schacht commanded the boat for its entire lifespan , receiving the Knight ' s Cross of the Iron Cross on 9 January 1943 in recognition of his successful patrols in the preceding year . He never wore his award however , as he was killed with his entire crew when the boat was sunk four days later . Service history . 1st patrol . Once the " U - 507 " had completed her working up period of six months following her commissioning , she departed German waters and entered the Atlantic Ocean for her first patrol ; an uneventful and simple cruise to Lorient in occupied France , which was to be her permanent home port for the remainder of her life . 2nd patrol . The second patrol was more eventful , as the boat rounded Florida at the end of April 1942 , taking full advantage of the lit - up settlements on the shoreline to pick and choose her targets amongst the unescorted shipping which bottlenecked between Cuba and the Floridan peninsula . Here she sank four large cargo ships in three days before following the coastline along Western Florida and Alabama , where in three more days she sank four more large unprotected ships , making full use of the failure of the local authorities to enforce either convoy regulations or the blackout . On 6 May she sank the about 45 miles south - southeast of the mouth of the Mississippi River . On the 12 May she sank the 10 , 000 ton SS " Virginia " in the mouth of the Mississippi , killing 26 sailors in an audacious attack which shocked the American authorities . Swinging south , she sank a Honduran freighter as she cruised out of the Caribbean Sea , leaving a shaken seaboard behind her . On this cruise alone she had sunk nine ships totalling 45 , 000 tons . 3rd patrol . Her third patrol was even more controversial , as a fruitless passage across the Atlantic brought her to the Brazilian coast in mid - August 1942 . There she searched for Allied shipping hugging the coastline in Brazilian territorial waters heading for North America . Here she again saw unescorted ships and a lit coastline , and Schacht made the inexplicable decision to attack without first ascertaining the nationalities of her targets . The first was the SS " Baependy " on 16 August , which was torpedoed and sunk with 270 civilian lives . A few hours later the SS " Araraquara " was sunk , killing 131 people , followed by the SS " Annibal Benevolo " , on which 150 civilians drowned . The next day the slaughter continued , the SS " Itagiba " sunk within sight of the city of Vitória , killing 36 , and the SS " Arara " similarly sunk with 20 deaths as she picked up the survivors of the " Itagiba " . Two days after this , the tiny sailing vessel " Jacyra " was sunk , and a Swedish ship was torpedoed three days after that . In just one week , " U - 507 " had sunk seven ships of 18 , 000 tons and killed over 600 people , all of them neutral civilians . The political ramifications of what Schacht and his crew had done off the Brazilian coast were enormous . Brazil went from a neutral favourable to Germany to an enraged opponent in the space of 48 hours , declaring war on Germany and supplying a Brazilian Expeditionary Force to the war in Europe and a squadron of ships to the Atlantic . More importantly , Brazilian Air Force bases were made available to American naval air squadrons , thus denying the U - boats their previous advantage of hiding in Brazilian coastal waters , and giving the Allies air cover across most of the Southern Atlantic , making the job of the U - boats significantly harder . In addition , Germany ' s standing amongst neutral nations , particularly the formerly pro - German dictatorships of South America , was in tatters , never to recover . The third patrol of " U - 507 " , was also highly significant , as after two months ineffective cruising between the West African and Brazilian coasts of the South Atlantic , " U - 507 " received a radio call from on 15 September reporting that she had sunk a ship carrying 1 , 500 Italian prisoners of war . This ship was the , and " U - 507 " made all haste to aid in the rescue operation , collecting a large number of survivors on board and towing several lifeboats , until attacks by American aircraft on the rescuing submarines forced her to dive and escape . She returned to Germany with her human cargo , and there received the orders which were the end result of the Laconia incident , which consisted of a total ban on aiding shipwreck survivors , except ships ' officers who were to be captured for information purposes . 4th patrol . On her fourth and final patrol she put this information to full use , as she sank three British ships off the Northern Brazilian coast , and captured the masters of all the ships , J . Stewart , F . H . Fenn and D . MacCullum . These victories had taken her into 1943 with a reputation for success , confirmed when her captain was informed of his Knight ' s Cross award . Sadly for him , the crew and the captives , just four days later the " U - 507 " was spotted by an American Navy PBY Catalina aircraft of VP - 83 flying from a newly available Brazilian base , which dropped several depth charges on the boat . The site of the attack was 330 miles from shore at Cape Saint Roque in Brazil , and there were no survivors , the 56 dead including Schacht , the captives , and the boat ' s new captain Heinz Radau , who was conducting an observation and familiarization patrol .