I was a Seaman (SS) in Hardhead when we were involved in Operation Mariner 1953, a NATO exercise covering most of the North Atlantic that Fall. For one phase of the exercise, we were in the Orange Force, patrolling off Newfoundland to intercept Blue Force units attempting to cross the Atlantic. Our patrol area was at the extreme southwestern end of the corridor through which the Blue forces were to sail, they being required to pass through certain designated way points. We patrolled submerged near the southwest end of our patrol area, snorkeling as needed and mainly listening for anything approaching. Mid-morning one day, sonar detected a noise level to the southwest. We stooged around submerged as the noise increased in intensity. Eventually, a periscope sighting of masts and stacks of warships was made and the ship went to g.q. I was a member of the sonar plotting team in the control room and we began a plot to complement visual data for an approach, but almost immediately, the vessels turned away and we lost sight of them. The captain (V.L. Vitucci) reasoned that they were on a zig-zag plan and might re-enter our area further along, so we ran at high speed under snorkel for a couple of hours, then slowed and listened. Again, a noise level approaching us. Soon, a carrier task force came in sight with the Bennington in the center. We went to g.q. again and began a sonar plot. This time, they were going to pass right over us, so we went deep for a bit until the screen had passed, then came back to periscope depth. We had kept the sonar plot going so when the scope was clear we had them in the crosshairs. But the proximity of the "enemy" meant that periscope exposure was kept to an absolute minimum, hence our sonar plot was critical. The change of bearing and bearing rate were right in the groove for a ninety degree track at rather close range so water slugs and a green flare were prepared for firing. At the optimum moment, we fired our slugs and the flare to indicate a torpedo attack. But just then, the sonarman hollered into the phone "She's gonna hit!" Immediately, the order was given to flood negative and take the boat down. We had just got a good down angle on when we were rammed. No matter where you were in the boat, it sounded like we had been hit right overhead in your compartment. The ship vibrated like a tuning fork for a few seconds, then the sound of screws passing overhead was heard. Again, you expected to see a bronze prop blade slice through the overhead as we all looked up. But nothing more happened. Even before the word was passed to rig for collision, the hatches and bulkhead flappers were clapped shut and we continued to go deep. Compartments were asked to assess any damage but nothing internal was found. The only significant problem was that the rudder could not be put on full right . The sounds of the task force began to diminish and we received a general message on Gertrude saying that the area around us was clear and to surface. Our slugs and flare had registered our presence, and some ship had felt some kind of a jolt. Later, the Captain told us that he had made a sweep around with the scope and spotted a cruiser due to pass close but clear. Apparently, they had just started a zig when we fired. But the Skipper decided that since we were still intact and not leaking, we'ed continue the game. Soon, it was evident that two DDs were standing by upstairs and they read our silent message and began to try to track us. By now we were on silent running and running our sonar plot on new targets. The cat-and-mouse lasted for several hours after that. The air was getting thick, so CO2 absorbent was spread and those not involved in the plot, etc. were ordered to turn in to conserve oxygen. Finally, around midnight, the DDs were some distance away presumably tracking a school of fish or a whale, so we came to periscope depth, made a visual and sonar approach and fired some more slugs and flares. Later, it was reported that the umpires credited us with putting two fish into the Bennington and one in each DD. By the time we surfaced, it was pitch black. The sail was intact so we had to wait for morning twilight to find out where we had been struck. With the sunrise, we found that the turtleback had been smashed over to port as though by a giant hammer. Closer examination showed that if we had taken the hit a foot further forward, tubes 7 and 8 would have been ripped out and we would have gone down stern-first in 2300 fathoms. As it was, we were able to continue to participate in the exercises, with a short break anchored in the roadstead of Reykjavik with liberty ashore. After that, we patrolled the Denmark Strait until we were part of a search line looking for the crew of a patrol plane that had had to ditch. No luck. During our return to New London, we passed through three storm fronts. At times we ran with the OOD and one lookout on the bridge with the bridge hatch closed and dogged, taking green water in the bridge. After two days back at State Pier, we ran up to Portsmouth to get a new turtleback put on. End of story. Happy ending - nobody died. I believe that if we had not flooded negative and not taken a down angle, we might not have been hit. But the down angle brought our stern up near the surface and Whango! The preceding by John F. Battick, Ph.D., Prof. of History Emeritus, University of Maine, and cousin of the John Batick who perished when Squalus went down in 1939.