About 04.15 hours on 21 May 1942, U-103 fired from about 400 yards a star shell across the bow of the unescorted Elizabeth (Master Walter Gwynn Hudgins), which was en route on a zigzag course at 11 knots about 30 miles south of Cape Corrientes, Cuba. Three minutes later a shell struck the stack. At 04.35 hours, one torpedo was fired that struck the port side between the #3 hatch and the engine room. The explosion killed the three men on watch below and destroyed the main steam line, the condenser, the shelter deck and the radio shack. The ship quickly stopped and the radio operator sent distress signals and received acknowledgments. The armed guards fired two shots from the after 4in gun (the ship was also armed with two .30cal guns) at the U-boat but missed. Ten minutes later the complement of eight officers, 27 men and seven armed guards abandoned ship in one lifeboat and one raft. After another ten minutes the vessel sank stern first. Three men on the raft were never seen again. 21 hours after the attack the remaining 36 men landed on the western Cuban coast, halfway between Cape San Antonio and Cape Corrientes.

The master Walter Gwynn Hudgins had already experienced a sinking, when his former ship, the Barbara, was sunk by U-126 (Bauer) on 7 Mar, 1942.