I just recently read the book, and translated verbatim to a movie, it would make for an incomprehensible mish-mash to the average moviegoer as the Captain did most of the tactics in his head, and much dialog happened in his mind. There is much rich earth to till in the story, and a master movie maker and a star like Hanks could do it justice, just not in its original form. There may have been one error in Forester's recitation of a blizzard of bearings and turning directions the Captain had to keep in his head throughout the story. I am a trained and certified anti-submarine officer, and back when I went through training the ASW school had to train us, albeit briefly, in dropping depth charges because there were still a couple of ships with them. We learned on the latest in WWII equipment including a bearing recorder using an impression paper roll and the strikers which marked it, an item mentioned briefly in the book. Much of our training had more to do with modern sonars and ASW torpedoes and the nuclear depth charges we carried. The book accurately describes the cone of silence as you close in on the sub to drop charges and, yes, they could do some evasion in the brief time of loss of contact during the typical 12-knot destroyer attack speed (over that speed cavitation starts to obscure the reception). We played at out guessing the submarine moves the simulator operators would input just as the protagonist in the book did. What I found most inaccurate in the book was the skipper's taking ALL the reins of the fight into his own hands. To maintain a single character-centered story, Forester used the reasoning of the protagonist that this was necessary because of the inexperience of his officers, but in Navy I lived in from age 18 to 42 no skipper would ever do that, regardless of the experience level of the people under him. What I and every other commanding officer learned to do was to weigh in a bit where there may be a steep learning curve for the officer concerned and to have a very light hand where competence is demonstrated. You direct and monitor your people to accomplish the various functions involved in ASW in order to keep the big picture in mind. The Good Shepard simply does it ALL by himself with only a tiny nod to one of his officers who seems to be "getting it." When I was ASW officer, I stood on the bridge next to the captain with sound-powered phones on with one ear free to him and the other ear listening to the evaluator at the Dead Reckoning Trace (DRT) table in CIC behind the bridge and the sonar supervisor (my chief sonarman) down in the bowels of the ship. I directed the officer of the deck to drive the ship around as the evaluator and I determined necessary while the skipper might talk to the assist ship out on the "fence" and keep an eye out for safety. The captain could and would be free to flit back into CIC to see the picture as it developed on the DRT but would be on the bridge for me to coach him through the mock nuclear weapon firing procedure and the actual shooting of conventional training ASW torpedoes fired by sonar control with settings I determined and at my command. It was a team effort then and it was in WWII as well.
