At 05.34 hours on 17 May 1942 the unescorted Gulfoil (Master A. Henry Rowe) was torpedoed by U-506 about 75 miles southwest of the Mississippi River Delta. The ship had maintained a zigzagging course up to 05.00 hours that day at 9.5 knots. The mate on watch spotted the first torpedo before it hit the starboard side amidships at the #4 tank. The explosion blew the catwalk away from the mainmast to the midships house. 15 seconds later, a second torpedo struck the engine room, killing the three men on watch below. After the first torpedo the vessel list about 40° to starboard, but partially righted herself after the second hit. The tanker sank within two minutes with a heavy starboard list. The crew had no time to launch the boats, only five officers and 14 crewmen out of eight officers, 28 crewmen and four armed guards (the ship was armed with one 4in and two .30cal guns) managed to leave the ship on two liferafts. After 35 hours, the survivors were picked up by the Benjamin Brewster and taken to Galveston, Texas.