Submarines are among the most sophisticated machines ever created, designed to operate deep beneath the ocean’s surface while remaining undetected for weeks or even months at a time. Within their steel hulls, sailors navigate tight passageways and live without sunlight, separated from the natural cadence of life above.
Daily life follows a rigid structure built around rotating 18-hour schedules, shared bunks, and carefully organized routines that leave little room for personal space. Yet these demanding conditions often strengthen camaraderie. Facing isolation, confined quarters, and constant danger requires mental toughness and unwavering trust, forging a distinct bond among those who serve in the quiet depths of the sea.
Overview of how submarines have developed over the years
USS Indiana (SSN-789) departing from Port Canaveral, Florida. (Photo Credit: Paul Hennessy / NurPhoto / Getty Images)
Nuclear-powered submarines integrate nuclear storehouses, launch platforms and weaponry to present an elusive and formidable package. Before the New Strategic Arms Reduction Treaty (START), the US Navy’s 14 Ohio-class ballistic missile submarines were armed with 24 submarine-launched ballistic missiles, each carrying multiple warheads. As per the treaty, each is now limited to a maximum of 20.
Typically, submarines embark on 77-day sea patrols, equipped with a 90-day food supply, before returning to port for just over a month. The Navy’s ballistic missile submarines operate with two alternating crews – Blue and Gold – maximizing their operational efficiency and minimizing the number of vessels deployed.
The inaugural combat submarine, designed during the American Revolution, was the Turtle. This roughly eight-foot spherical vessel held a single individual and was manually powered. Shortly after her development, Turtle executed the world’s first submarine attack by stealthily navigating underwater, penetrating the HMS Eagle (1774) and installing explosives in her hull.
In contemporary times, submarines like the Ohio-class boast an impressive length of 560 feet and a weight exceeding 18,750 tons when submerged. The Navy’s submarine fleet comprises 53 fast-attack submarines, 14 ballistic missile submarines (holding more than half of the American nuclear arsenal) and four guided-missile submarines.
Personnel stationed on these submarines undergo rigorous training, including exercises like Ice Exercise (ICEX) 2022, preparing them to navigate complex and potentially perilous environments. Such training is crucial given the uncertainties associated with serving beneath the ocean’s surface.
What is downtime like inside a submarine?
Sailors onboard the USS Ohio (SSGN-726) watch the Super Bowl in the crew’s mess. (Photo Credit: Class Tristin Bomar / U.S. Navy / Getty Images)
Life aboard a submarine presents a unique set of challenges. Like sailors on surface vessels, submariners must contend with cramped quarters, limited space to move, and a restricted menu. But unlike surface ships, submarines offer no natural light, and even exercise equipment is specially engineered to operate quietly so as not to reveal the vessel’s position.
Despite these constraints, crews form bonds that often last a lifetime. Months spent in close proximity foster intense teamwork and camaraderie—qualities essential for mission success.
Submarine life also follows a highly structured routine, unlike anything on surface ships. Sailors rotate through three six-hour shifts: six hours on duty, six hours for personal time, and six hours for sleep, ensuring operations run smoothly and efficiently even in the confined underwater environment.
Dealing with deadly weapons onboard the vessel
Machinist’s mate onboard the USS Norfolk (SSN-714) securing a Tomahawk missile capsule to the pivot tray in the torpedo room following a successful launch. (Photo Credit: Renso Amari / AFP / Getty Images)
Taking care of weapons is one of the most important responsibilities for submariners. Although submarines often focus on patrol and surveillance, their missile systems are a vital part of military operations. To stay prepared, the crew must regularly check and maintain their weapons and other equipment so everything is ready to go at a moment’s notice.
The U.S. Navy plans to expand its fleet by adding up to three Virginia-class fast-attack submarines each year through 2043. Still, some experts—like former Submarine Forces Commander Vice Adm. Michael Connor—say that won’t be enough. He believes the Navy needs 66 more submarines to meet the rising need for strong underwater military power.
Looking ahead, the Navy is also working on replacing its aging Ohio-class submarines with the new Columbia-class. The first of these advanced submarines is expected to join the fleet by 2031.
Submarines play a critical role in deep-sea rescue
Pressurized Rescue Module of the Submarine Rescue Diving and Recompression System. (Photo Credit: Pablo Villagra / AFP / Getty Images)
Submarines are not solely instruments of war; they also provide access to some of the most remote and unforgiving regions beneath the ocean’s surface. These precisely engineered vessels allow humans to operate in extreme depths and stand ready to respond when emergencies unfold far below.
In the event of a disaster, Deep-Submergence Rescue Vehicles (DSRVs) serve as vital recovery platforms. Though compact in size, these U.S. Navy rescue submersibles are highly advanced, able to dive beyond 1,000 meters, attach to a disabled submarine, and evacuate trapped crew members. They are transported and launched from specially outfitted support ships known as MOSUBs, designed to withstand immense underwater pressure and function reliably during urgent rescue operations.
Comparable rescue systems exist beyond the United States. Countries such as the United Kingdom and France maintain their own deep-sea rescue capabilities, underscoring an international commitment to safeguarding submariners who work in one of the world’s most hazardous environments.
Life inside a submarine means dealing with navigational challenges
Sailors using the US Navy Submarine Combat Control System, which integrates seven sonar systems, weapons control, command and decision, and data fusion. (Photo Credit: Getty Images)
Despite seeming complex, steering a submarine is relatively simple—even though the person at the helm can’t actually see where they’re going. Instead of vision, submarines depend on sonar to identify nearby objects and hazards in the water. They’re also equipped with an inertial navigation system (INS), which tracks the sub’s position by measuring its motion over time.
Because GPS and radio waves don’t penetrate water, the INS plays a crucial role in navigation while helping the submarine remain undetectable to adversaries. This high-tech system uses gyroscopes and accelerometers to determine speed and direction.
One of the most iconic pieces of submarine equipment is the periscope. This tall, narrow instrument allows the crew to observe the surface while staying hidden beneath the waves. Some models can extend as high as 60 feet!
Has much has changed over the years?
(L) US Navy personnel on the bridge of a submarine as it enters the harbor during the Pacific Campaign of the Second World War + (R) Sailors assigned to the USS Albuquerque (SSN-706) stand watch as the vessel departs port. (Photo Credit: 1. US Navy / FPG / Getty Images 2. Jeremy Gross / US Navy / Smith Collection / Gado / Getty Images)
When comparing older submarines to their modern counterparts, it’s striking how similar they are, especially when looking at those used during World War I and II. Though these early subs were slower and couldn’t stay submerged for as long as today’s vessels, they still played a crucial role in reconnaissance and providing support at sea.
The most significant leap in submarine technology came after the war with the introduction of nuclear-powered submarines in 1954. Unlike their diesel-powered predecessors, these nuclear submarines marked the dawn of a new era. Their ability to remain submerged indefinitely, thanks to nuclear power, made them the first true submarines in terms of endurance and operational capabilities.