Since it's such tight quarters in the USS Louisville, Cmdr. Sager says some men sleep in the torpedo room. "Guys actually sleep between torpedoes down here," he says. "We make use of all the extra space that we have."

Bathroom space is also limited. Cmdr. Sager says the whole crew shares three bathrooms. "One of the bathrooms has three toilets," he says. "The other ones each have about one or two."

For this reason, Cmdr. Sager says the Navy doesn't allow women to serve on submarines. "They continue to look at that policy and evaluate it, but right now, we don't have any women on board, based on habitability and the personal space that everybody has."