Have you ever wondered what it takes to serve aboard a Navy submarine? To even be eligible, hopefuls must pass a rigorous series of psychological evaluations, intensive courses, and grueling tests. And once aboard, crewmen shoulder an 18-hour schedule that is divided into 6 hours of sleep, 6 hours of work, and 6 hours of training, drills, and sometimes a little free time.

According to Navy officials, these sailors are some of the most highly trained people in the Navy—training that is very necessary when operating in the deadly depths of the world’s oceans. The training involved is both technical and broad, as each member of the crew must possess the knowledge required to operate and service every piece of equipment aboard in order to respond to emergencies.

In short, it’s a hard job that only the best members of the U.S. Navy can do.

One of these highly skilled servicemen is Chesapeake, Virginia native and native and Deep Creek High School graduate Shea Roach, who now serves aboard the USS Tennessee—one of the world’s most advanced ballistic missile submarines.

Petty Officer 1^st Class Roach is a nuclear-trained machinist’s mate whose duties include operating, repairing, and maintaining his submarine’s propulsion machinery and related equipment—he keeps the reactor systems of the vessel running smoothly. And that’s no small tasks when your’re running hundreds of feet below the surface of the ocean.

The challenges of serving aboard a submarine are great, but so is the reward. These men—and now women, as well—give up the sun, eschewing the surface world in service to the greater good. And in giving up the sky for a few months in a dark, metal tube, they help safeguard our nation by ensuring the Navy’s submarines are operating at their best and are ready to respond to any emergency at a moment’s notice.

But despite the sacrifice, cramped conditions, and long hours, Shea Roach is focused on the bigger picture, and remains positive about his position. “The best part of being stationed on the submarine is the closeness of this group of people,” says Roach, according the Navy Office of Community Public Affairs. “The Navy has opened my eyes to different cultures and given me the opportunity to work with people from different backgrounds.”

Submariners typically deploy for six months at a time, during which they conduct a variety of missions vital to the security of the nation. Nuclear-powered submarines are powerful vessels that are limited only by the amount of food they are able to store aboard—their reactors last for the life of the ship, and air and water are constantly generated. The Navy’s ballistic missile submarines—affectionately called “boomers,” according to the Navy—act as undetectable launch platforms for intercontinental ballistic missiles, and are designed for stealth and extended missions.

This is one job that this Virginia will likely remember for the rest of his life—as much for the cramped spaces and shared bunks as for the opportunity to serve his country in one of the most unique and challenging ways possible.