This was a pretty solid supposed true story of a Russian submarine and its captains during the early 1960s. It's memorable, story-wise, for the radiation victims among the crew members. There are some really dramatic scenes involving that horrific event. Otherwise, it's a story of the sub's problems and the conflict between two captains.
The story starts slowly so you have to stick with it as it gets better and better as it goes on and rewarding enough to make you glad you hung in there for the whole 137 minutes.
Profanity is minor and the Russian accents are handled well by the lead actors, led by Harrison Ford, Liam Neeson and Peter Sarsgaard.
It's not a great film, but it's good and interesting enough to recommend a rental, but not something I'd watch numerous times. Those radiation scenes would be a little too grim to watch numerous times.