Date of Action: 13 June 1943
USCG Units Involved: USCGC Thetis
Location: 24.13N x 82.03W
Credit by U.S. Navy? Yes
Enemy warship's commanding officer: Korvettenkapitän Wolf Henne
Enemy casualties: 52 killed in action, no survivors
U.S.C.G. casualties: None
The U-157, a Type IXC U-boat, departed on her second war patrol from Lorient, Occupied-France, on 18 May 1942. She was ordered to operate in the western Atlantic. On 11 June she torpedoed and sank the 6,400-ton tanker SS Hagan off Cayo Guajaba, Cuba.
The next day, a radar-equipped B-18 bomber was sent out to search for the sub. Finding U-157 on the surface the bomber failed on its first pass to drop its depth charges. Turning sharply, the bomber sped back toward the sub and dropped four depth charges on the rapidly diving U-157. Henne and his crew narrowly escaped.
Meanwhile all available surface craft were dispatched to find the sub. Twelve Coast Guard patrol craft, including the cutters Triton and Thetis, several destroyers, and more aircraft were sent to locate the enemy. Groups from Miami and Key West made separate searches. Despite all the attention that Henne received he managed to escape the vessels. U-157, however, could not escape the aircraft which spotted his craft three times within a seven hour span and attacked once unsuccessfully.
The Key West group included the cutter Thetis. On June 13th, the group received word that a periscope had been spotted in the Florida Straits. Thetis and the Coast Guard cutter Triton along with the rest of the hunter killer group arrived and began setting up a search pattern in hopes of finding and destroying the enemy vessel.
The commander of Thetis was Lieutenant (jg) Nelson C. McCormick. McCormick graduated from the Coast Guard Academy near the bottom of his class in 1935. Receiving only a temporary commission he was not made permanent until more than two years after graduation. McCormick, however, had served on three different cutters and had commanded the cutter Dione. Working off the Coast of North Carolina he had already had a great deal of experience hunting U-boats.
At 3:30, An hour after beginning the search, the soundman on Thetis got a clear contact on the bottom. McCormick did not hesitate, having done this so many times before. Passing over U-157, McCormick turned Thetis around doing fourteen knots. He attacked the sub with seven depth charges, released at five second intervals and two from the y-gun. The charges were set at 200 and 300 feet and fell perfectly around the German sub. Wolf Henne and his crew never again surfaced. Debris from the submarine, however, did. The crew of the Thetis found a couple of pairs of pants and an empty tube stamped "Made in Germany." Five other ships made runs on the target to insure the kill, but Thetis sank the sub and received the credit.