潜艇的使用，使海战从两维成为了三维，更严重的改变则是对一些战争原则的颠覆，因为潜艇太适合做刺客工作了……苦挨深水炸弹是潜艇电影中都会作为重点的情节，在这个煎熬的过程中是否信任将自己包裹在内的这套钢铁装备，会使新人趋于崩溃，因此相比于舰艇兵，潜艇军人需要更多的勇气和决绝，特别是对敌人和自己人的残忍。
这部电影的主要展示点就是潜艇艇长的一个选拔标准是：敢于命令自己的士兵去死……于是伴随着兵不厌诈的伪装、杀俘、溺水等场面，主角在这个标准方面飞速的成长。以下的台词堪称经典：
I'm not questioning your bravery. The question is: what about their lives? You and Mr. Emmett are good friends. You went to the Academy together. Would you be willing to sacrifice his life? Or what about some of the younger enlisted men? I know a lot of those guys look up to you like a big brother. You willing to lay their lives on the line? You see? you hesitate. But as a captain, you can't. You have to act. If you don't, you put the entire crew at risk. Now that's the job. It's not a science. You have to be able to make hard decisions based on imperfect information. Asking men to carry out orders that may result in their deaths. And if you're wrong, you suffer the consequences. If you're not prepared to make those decisions, without pause, without reflection, then you've got no business being a submarine captain.
......
This is the navy, where a commanding officer is a mighty and terrible thing, a man to be feared and respected, all knowing, all powerful... the skipper always know what to do, whether he does or not... This is not a goddamn democracy!
...die trying, that ain't crazy. That's our job.
一触即发的深海战争
