(CNN) Sailing on a U.S. nuclear attack submarine is a trip into a cramped, timeless, windowless undersea world. My team and I got an exclusive trip on the USS Missouri during exercises in the Atlantic Ocean off the coast of Florida.

The first thing we noticed is how just how precious space is on board -- and how the crews, who spend six months at sea on deployment, manage to stay out of each other's way. About a third of the 337-foot vessel is taken up by the onboard nuclear reactor and propulsion, leaving a tiny living and work space for the sailors.

The Missouri spent 163 of 181 days underwater on its last deployment.

Every last inch is conserved and made ready for multiple uses. The officers' wardroom, where senior officers dine, doubles as an operating theater in medical emergencies. The torpedo room doubles as exercise room and sometimes bunkroom. Sleeping space is in particularly short supply. In fact, Virginia-class submarines like the Missouri have fewer beds than sailors -- about 94 for the 135 crew. That requires what the crews not so affectionately call "hot-racking," where sailors share bunks and sleep in shifts.

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Night and day are indistinguishable on board. It is an endless series of eight-hour shifts. To keep a sense of sanity, the mess rotates breakfast, lunch and dinner every few days so the late shift isn't stuck eating meat and potatoes for breakfast.

Personally, I was amazed at how deftly the crew manages confinement with a smile. Submariners have developed a long list of unwritten rules to help keep the peace, particularly on long stretches underwater. Crews don't talk politics on board. They don't slam doors, knowing someone is always sleeping. And they learn to bend, duck and dodge just to avoid running into each other walking back and forth through the tight hallways.

Submarines are an all-volunteer service, a fact that brings a certain amount of pride. And submariners grant it is a certain kind of person who chooses a life under the sea. That pride is the true secret to keeping the peace. They each respect the sacrifice they're all making -- a special camaraderie built on shared sacrifice.

So how do they pass the time aboard a small enclosed vessel with 130 other sailors so close together?

"Working out," one sailor aboard the Missouri told me while also adding, "I personally spend a lot of time playing cards, or just staying away from other people I don't want to be around."

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"It depends on the day," another sailor told me. "Sometimes you go find a quiet corner and read a book," or watch a movie with your buddies on the projector in the crew's mess or the cafeteria aboard the sub.

While politics is a seldom discussed topic, the sailors said the "politics" of sports, and how one's team stacks up against another, is always fair game.

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"Slamming doors" and other loud noises, multiple sailors said, because sleep is at a premium in an environment of staggered shifts aboard an enterprise operating 24 hours a day.

There is also the etiquette of shower time -- three to five minutes being what these sailors constitute as being considerate of others since it is all about the "water run time" and the cycling out of dirty water for clean water these sailors must do.

Because of their extended periods beneath the surface, submariners are also allowed certain liberties that others in the Navy are not, such as growing beards to a certain length and a less regimented directive on hair length and style.

One sailor said some aboard the Missouri have taken part in a "Mighty Mo" contest -- a play on the nickname of the Missouri -- where they see who can grow the best Mohawk.

U.S. Navy's submarine fleet The USS Michigan, an Ohio-class guided-missile submarine, arrives in Busan, South Korea, for a routine port visit in December 2010. Click through the gallery to see some of the other subs in the U.S. Navy's fleet. A dolphin swims in front of the Virginia-class attack submarine USS John Warner during its sea trials in May 2015. Virginia-class subs, displacing 7,800 tons and at 377 feet long, "are designed to seek and destroy enemy submarines and surface ships; project power ashore with Tomahawk cruise missiles and special operation forces (SOF); carry out inntelligence, surveillance, and reconnaissance (ISR) missions; support battle group operations; and engage in mine warfare," according to the Navy. The Ohio-class guided-missile submarine USS Georgia (SSGN 729) departs Naval Submarine Base Kings Bay to conduct routine operations in October 2015. The USS Seawolf, shown here in support of European operations in June 2015, is the lead vessel in the three-boat Seawolf class. The Seawolf and the USS Connecticut, the second boat in the class, displace 9,138 tons and are 353 feet long. Click to the next slide to learn more about the third sub in the class, the USS Jimmy Carter. The Seawolf-class attack submarine USS Jimmy Carter is moored in a Washington state facility that reduces a ship's electromagnetic signature in 2006. The Jimmy Carter is 100 feet longer than the first two subs in its class. The extra space is for a "multimission platform," the Navy says. "This hull section provides for additional payloads to accommodate advanced technology used to carry out classified research and development and for enhanced warfighting capabilities." The U.S. Navy has more than a dozen ballistic missile submarines, also called boomers, in service. The boomers, 560 feet long, can carry 24 nuclear-armed Trident II ballistic missiles and serve as nuclear deterrents. Here, the Ohio-class ballistic-missile submarine USS West Virginia departs a naval shipyard in 2013. The Ohio-class guided-missile submarine USS Ohio transits Puget Sound, Washington, in June 2015. The Ohio and three other guided-missile subs -- USS Florida, USS Michigan and USS Georgia -- were originally built and deployed as ballistic-missile subs, but were converted to guided-missile platforms beginning in 2002 after the Navy concluded it had a surplus of the boomers. The Los Angeles-class attack submarine USS Hampton surfaces through Arctic ice in March 2014. The Los Angeles-class is the biggest in the Navy's sub fleet, with a few dozen in commission. These subs displace 6,900 tons and are 360 feet long. The class was introduced in 1976.

And they make a lot of sacrifices. When they're at sea, submariners have limited contact with home. Emails come and go only when the submarine surfaces, which was for fewer than 20 days during their last six-month deployment.

And even then, communication isn't guaranteed. Any time the submarine sends a signal, it identifies its position, and loses the secrecy that is at the core of the crew's mission. There is only one washer and dryer on board, so clean clothes are a luxury. But submarines are famous for their good food, always topped off with a desert or two, including ice cream. Movies and cell phone video games are another welcome break.

But the traditional pastime is decidedly old-school: cribbage. I got drafted for a few games -- and let's just say I was not up to Navy spec.

Sleeping on board was oddly comfortable for this first-timer. The bunks are tiny; stretched out, I felt like I was in an MRI machine -- or worse, dozing off in a casket. But the hum of the boat lulled me to sleep for a solid few hours undisturbed.