During the Battle of the Atlantic, Charles Gerlach of Rapid City was aboard the escort carrier USS Guadalcanal, backed up by 5 escort destroyers, as it captured the German submarine U-505, now in Chicago's Museum of Science and Industry (click to go inside, picture below).  The U-boat contained highly classified codebook translation formulas, a huge advantage for intercepting enemy military plans.  The capture was kept top-secret for the rest of the war. Though the Allies had the Enigma cipher machine itself the year before, historian David Kahn has noted that "The capture of the U-505 by an American task force on June 4, 1944, provided a copy of the Adressbuch that provided the keys for disguising grid positions; from then on the Allies read them as easily as the Germans did."  Gerlach added that “We almost lost the Battle of the Atlantic.  They were sinking our ships faster than we could build them." 

Before I tell you about the capture of the U-505, the only enemy warship captured on the high seas since the War of 1812, I want to tell you a little bit about the escort carriers. In the early days of battle of the Atlantic, when the German submarines were sinking our ships faster than we could build them, it became obvious that we had to have air cover out where our land-based planes could not go. In desperation the navy slapped a flight deck on an old collier, christened her the Long Island CVE 1 and sent her out to escort convoys. Then in quick succession came the Bouge, Cord, Core, and Block Island, which were converted cargo ships. These were followed by the Sangmon, Suwanee, Chenango and Santee, which were built on hulls already laid for fleet tankers. Some of these ships were deployed to the Pacific Theater, including the last four. The Santee took a kamikaze hit at Leyti Gulf, and the Block Island was sunk by a German sub.
     These ships were so successful that Henry Kaiser shipyard in Tacoma, Washington, was selected to build a class of CVEs called the Casablanca class, designed as such from the keel up. There were 550 feet long, 55 feet wide with a flight deck 55 feet above the water. You could put two of them on the flight deck of the Forestall and still land airplanes. When the Kaiser yard got into the act, they spit those little buggers out like a farm boy with a mouthful of sunflower seeds. My ship, the USS Guadalcanal CVE 60, was the 5th of these ships to come down the ways, we put her into commission in Astoria Oregon, and outfitted her in various West Coast ports. 
    In the fall of 1943 we came through the Panama Canal and sailed on up the East Coast to Portsmouth, Virginia, our home port.  There we became the flagship of Hunter Killer Task Group 22.3.
     My rating at that time was aviation machinist mate 1st class.  My specialty was catapult technician. I was assigned to the catapult crew which consisted of 7 enlisted men and the catapult officer. This was just enough men to run the catapult operation.
     Our normal operation for the day was to launch a flight of two to four planes every four hours during the day and every two hours at night. We did this every day through all kinds of weather. It was not uncommon to see waves breaking over the bow between catapult shots. All bombers and most fighters had to be launched by catapult. So you see, I soon learned I could get along without sleep—almost.  We maintained complete radio silence, and we didn't have GPS in those days.  Those amazing pilots flew those difficult missions with nothing more than a compass and a navigation pad strapped to their leg.  When returning to the rendezvous area at night, they could find the ship only by approaching it from dead astern, where they could see two rows of glow lights marking the deck.
     We would leave port and hunt for a month to 6 weeks, then reprovision in Casablanca, Morocco, and hunt back again.
     On our first trip we got 2 “possibles” (we felt sure they were kills) but we didn't get credit for them because we didn't have enough evidence. The captain said “If we have to bring one back, by golly we will."  The next day we started having boarding and salvage drills. 
     We were pretty busy for some time prior to this engagement.  I remember Holy Week that spring.  We were at GQ almost the whole week. The contacts were quite frequent right up to the day of the capture. On June 3rd we had a strong contact but lost it. The Germans had a sneaky habit of dropping below the thermocline where our sonar couldn't find them--but they couldn't stay there forever. We were off the coast of West Africa and nearly out of fuel and due to go in to Casablanca.
     The next day was Sunday. We were flying minimum air cover due to fuel shortage. We had just returned from church service when GQ sounded. We immediately launched more aircraft. There was a strong contact close by. The destroyers began laying depth-charge patterns and soon visual contact was made from the air.  Two torpedo wakes were sighted coming our direction but neither hit any thing.  The sub surfaced a few hundred yards from the carrier, and the captain immediately ordered the heavy ordinance to cease fire and to fire only anti-personnel ammo.  The Germans began to abandon ship and the captain ordered all boarding and salvage parties away. The sub was down at the stern partially flooded, with the bow and conning tower above water. It was circling with an 8 degree jammed rudder, held up only by its diving planes and electric motors. The batteries were nearly run down and the sea cock was open, flooding the vessel, so time was critical. 
     The sub was so low in the water that as the boarding party entered, the hatch was dogged down, so it was either do or die for them to find and disarm the known 19 booby traps and close the sea valve.
     They were able to save the ship and capture the log books, the code books and above all the Enigma machine. The sub was taken in tow by the carrier because nothing in the fleet was big enough to pull it. 
     Because the West Coast of Africa was a nest of German spies, we were not allowed to go to Casablanca--but ordered to proceed to Bermuda, 2500 miles away.  A fleet tanker came out to refuel and provision us. 
     It was vital that secrecy be maintained because, if the Germans knew we had captured their boat, we would have had every sub in the Atlantic after us.   And unbeknown to us, the next day was D-Day at Normandy.  lt surely would made a great difference if the enemy knew we had broken their code. The amazing thing about this operation is that although there were about a thousand people involved, it was one of the best-kept secrets of the war. Even our wives didn't know about it until the war was over. 
     One other thing I would like to say, I don't think think there was another captain that could have pulled operation off.  Captain Daniel V. Gallery was the type of skipper the men would gone through hell for.  He knew how to treat men to get the most out of them. For instance, when we would pull into home port, the first people down the gangway would be the leave party, and the second party would be the liberty party.  And he was the only skipper so far as I know to hold regular boarding-and-salvage drills in the preceding 100 or so years.
    This capture was no accident.

Charles Gerlach, May 8, 2010 (Photo by Duke Doering) when speaking to the Black Hills Veterans Writing Group