In September 1943, Gallery returned to the U.S. and was appointed commander of USS Guadalcanal. In January 1944, he led USS Guadalcanal in Task Group 21.12, which sank three German Submarines: U-544, U-515, and U-68.
"I Think We Can Capture a U-Boat"
During his last antisubmarine patrol with Task Group 21.12, Gallery began to think it might be possible to capture a U-boat. It would be a monumental feat and provide the Allies with secret German naval technologies including U-boat torpedo guidance systems, communication codes and the attack tactics used by U-boats.
Upon returning to the U.S. in April of 1944, Gallery ordered each ship in the Task Group to prepare a plan for capturing, boarding and towing a U-boat. The boarding parties began their training exercises immediately, though there were many unknowns in preparing for something that had never been done before.
In May of 1944, the Hunter-Killer Task group 22.3, with Gallery in command, set sail into the Atlantic with authorization to capture a U-boat, if possible.