With deployments underwater typically running 90 days, life onboard a submarine is anything but normal.
Cramped quarters are the norm, and sailors must have the right technical know-how as well as determination to spend months underwater at a time.
To even be eligible to be a crewman aboard a submarine, applicants must pass a series of grueling tests, psychological evaluations, and intensive courses.
Continue reading and slideshow at CRAMPED, ISOLATED, AND HEAVILY-ARMED: What life is like on a Navy submarine
