Submarine Corvena (uncredited) Milburn Stone Ground Control Officer (uncredited) Frank Sutton as Chief Gunners Mate (uncredited) Louis Mosconi as Radarman Mosconi Production John Wayne and Patricia Neal did not get along during filming. Nearly fourteen years later, however, they worked together on In Harm's Way (1965) where she noted that he had mellowed a lot, possibly because he was seriously ill with lung cancer at the time. The film's opening foreword and dedication states: "When the Pacific Fleet was destroyed by the Japanese sneak attack on Pearl Harbor, it remained for the submarines to carry the war to the enemy. In the four years that followed, our undersea craft sank six million tons of Japanese shipping including some of the proudest ships of the Imperial Navy. Fifty-two of our submarines and thirty-five hundred officers and men were lost. It is to these men and the entire Silent Service that this picture is humbly dedicated." The special mission shown at the beginning of the movie, in which Navy submarines ran war supplies into the Philippines and evacuated civilians, while idealized is a matter of historic record. By the time of the invasion of the Philippines in 1944, these supply runs had enabled American and Philippine Army officers who had refused to surrender to build a military organization in the islands that was the size of an army corps. The numerous problems with the Mark 14 torpedo and its Mark VI exploder depicted in the film are accurate. A poorly designed and tested firing pin could malfunction on a good hit (that is, a torpedo striking within about 45 degrees of perpendicular to the side of the target). Poor hits (at a very sharp angle to the side of the ship) could often produce more reliable explosions. Diagnosing the problem actually did occur in a similar manner after 20 months of repeated failures in combat. Submarine crews were involved in the testing, although not in the capacity shown in the film. The scene where Commander Perry (Bond) is killed in a surface action is a combination of two incidents involving Commander Howard W. Gilmore, captain of . Mortally wounded on the bridge, Gilmore gave the order "Take her down!", sacrificing himself to save his submarine and crew, for which he was posthumously awarded the Medal of Honor. The ramming and sinking of the armed freighter depicted in the scene occurred in the