At 23.55 hours on 7 Oct 1942 the unescorted Boringia (Master Sofus Heinrick Konard Kolls) was hit on the starboard side in the fore part of #3 hold by one torpedo from U-159 while steaming on a non-evasive course at 13 knots about 120 miles west-southwest of Capetown. The U-boat had first spotted the vessel with its navigational lights set about 3 hours earlier and did not attack because the BdU had ordered all U-boats operating off South Africa to wait until 10 October, but shortly thereafter received a change of orders and then managed to locate her again. The ship immediately stopped after the hit because the engine room flooded through a destroyed bulkhead and settled rapidly on an even keel. The crew began to abandon ship in all four metal lifeboats and tried to send a distress signal but they were unable to do so because the aerials had been damaged by the explosion. At 00.06 hours on 8 October, a coup de grâce struck on the starboard side in the engine room and caused her to sink after 10 minutes. Unfortunately both starboard boats were still alongside and the explosion destroyed both, killing most occupants and the chief officer standing on deck where the torpedo struck. His wife, serving as stewardess aboard, was badly injured and later lowered into one of the intact boats. 21 crew members and four gunners (the ship was armed with one 4.7in, one 12pdr and four machine guns) were lost. The Germans questioned the survivors in one of the boats and gave them the direction to the nearest land, but misidentified their victim as the motor merchant Selandia (8482 grt).

The master, 33 crew members and one gunner in two lifeboats set sail towards Capetown and were picked up less than 7 hours after the sinking by the Clan Mactavish, which was sunk by the same U-boat at 09.07 hours on 8 October. Six crew members and the wounded stewardess from Boringia died in the second sinking. The master, 26 crew members and one gunner were later that day picked up by the British steam merchant Matheran and landed at Capetown on 9 October.