Operation Teardrop

The following description was copied from Wikipedia.

Operation Teardrop was a United States Navy operation during World War II, conducted between April and May 1945, to sink German U-boats approaching the Eastern Seaboard that were believed to be armed with V-1 flying bombs. Germany had threatened to attack New York with V-1 flying bombs and rocket U-boats. After the war, it was determined the submarines had not been carrying either.

Operation Teardrop was planned during late 1944 in response to intelligence reports which indicated that Germany was preparing a force of missile-armed submarines. Two large U.S. Navy anti-submarine warfare task forces were set up. The plan was executed in April 1945 after several Type IX submarines put to sea from Norway bound for North America. While severe weather conditions in the North Atlantic Ocean greatly reduced the effectiveness of the four U.S. Navy escort carriers involved, long patrol lines of destroyer escorts detected and engaged most of the German submarines. Aircraft of the Royal Canadian Air Force supported this effort.

Five of the seven submarines in the group stationed off the United States were sunk, four with their entire crews. Thirty-three crew members from U-546 were captured, and specialists among them were interrogated under torture. One destroyer escort was sunk, with the loss of most of her crew. The war ended shortly afterwards and all surviving U-boats surrendered. Interrogation of their crews found that missile launching equipment was never fitted to the U-boats, which was further confirmed after the war.

The following link will take you to a very descriptive document on Operation Teardrop. It is posted on a web page by the Naval History and Heritage Command.