 U @-@ 38 would spend two and a half months in port , before leaving for operations off the west coast of Africa on 9 April 1941 . This would prove to be her most successful patrol , with the sinking of eight ships . On 4 May , the Swedish steam freighter SS Japan was torpedoed while traveling with Convoy OB @-@ 310 from England to the United States . The following day , the British motor freighter MV Queen Maud was hit and sunk . On 23 May , the Dutch motor freighter SS Berhala was sunk while traveling with the Convoy OB 318 , from England to America . The British steam freighter SS Vulcain was torpedoed and sunk on 24 May . Six days later , on 29 May , the British steam freighter SS Tabaristan was another victim . The following day the destruction continued , the British steam freighter SS Empire Protector was sent to the bottom , as was the Norwegian steam freighter SS Rinda on the 31st . The eighth and final ship sunk during U @-@ 38 's eighth patrol was the British cargo steamship SS Kingston Hill on 8 June . The boat then returned to Lorient on 29 June 1941 , after spending eleven and a half weeks at sea . 
