Dangerous Ground - Larry Bond Let's see. Hero is transferred from aviation branch thanks to influence by relative. Suffers abuse on board sub because of it. Mean but in the end kind captain. Hero overcomes hardships. Makes friends with girl on board (scientist checking out new prototype.) Helps evade attacking Russians. Lots of nifty technical detail. Mix all these standard plot elements together and you have a decent if many-times-done-before-story.