Daily Life on a Nuclear Submarine: The Smell, The Stress, and The "Happiness Factor"

By Tony Grayson, Tech Executive (ex-SVP Oracle, AWS, Meta) & Former Nuclear Submarine Commander

Published: December 14, 2025 | Last Updated: December 22, 2025

The human element inside the steel tube. Me (center) and my wardroom in the control room of the USS PROVIDENCE. Moments of camaraderie like this are essential to maintaining the "Happiness Factor" during long deployments.

TL;DR — Key Takeaways

• The smell is real. Amine (monoethanolamine) from CO2 scrubbers permeates everything—clothes, skin, hair. Your brain tunes it out after 24 hours, but everyone at home smells it on you.

• Hot racking means sharing beds. Fast Attack submarines have more crew than bunks. You crawl into a coffin-sized space still warm from the last guy.

• Complete isolation for months. No internet, no news, no real-time communication. Text-only Sailor Mail when you surface—screened and delayed.

• The Happiness Factor keeps you sane. Days of Leave ÷ Days Left on Mission. When that ratio exceeds 1.0, you've beaten the boat.

I spent 21 years in the U.S. Navy, finishing my career as the Commanding Officer of the USS PROVIDENCE (SSN-719). I often talk about submarine leadership on LinkedIn, but when people Google "daily life on a submarine," they usually find dry technical specs or recruiting posters.

The reality of living 400 feet underwater isn't about specifications. It is about sensory details. It’s about how we sleep, the specific smell that sticks to our clothes, and the mental math we use to survive months of isolation.

There is a specific moment in every deployment when the math changes—when the suffering becomes mathematically cheaper than the reward. We call it the "Happiness Factor."

But before we get to the math, we have to talk about the plumbing.

Submarine Toilets: Where Do You Poop?

The most common question civilians ask is the one they are usually too polite to say out loud.

It depends on the boat. Boomers (SSBNs) are larger ballistic-missile subs; Fast Attacks (SSNs) are smaller, hunter-killer boats built for speed and stealth. If you are on a Boomer, life is relatively luxurious with standard flushing toilets.

But if you are on a Fast Attack (like the Providence), going to the bathroom is a high-stakes evolution. We often use a manual ball-valve system. This isn't just pushing a handle; it involves a precise sequence of opening and shutting valves to flush waste into the sanitary tank.

On almost every deployment, someone doesn’t read the placard. They open the inboard valve while the outboard pressure is high. The result? The contents of the tank—under high pressure—reverse course back into the stall.

When sewage hits you at high velocity, your first instinct is to scream. That is the exact opposite of what you want to do. We called these sailors "Shitscreen," a nickname that invariably stuck for the rest of the deployment.

The Happiness Factor: How We Stay Sane

Once you survive the plumbing, the next challenge is your own mind. People ask if submariners go crazy from the isolation. We don't, because we turn morale into math.

We utilized a mental model called the Happiness Factor.

Survival isn't just about grit; it's about calculating leverage. Onboard, we didn't just count days; we calculated the ratio of future suffering to future reward.

The Formula: Happiness Factor = Days of Leave Approved / Days Left on Mission

Let's say I have 20 days of watchstanding left and only 5 days of leave approved. That’s a happiness factor of 0.25. That is misery. The "cost" of the mission outweighs the reward.

But then comes the tipping point. I remember a specific moment: Day 72 of a long patrol. I was tired, the coffee was bad, and I hadn't seen the sun in two months. I looked at the calendar. I had 18 days left underwater, but 21 days of leave approved.

21 ÷ 18 = 1.17.

The Happiness Factor was greater than 1. We had mathematically beaten the boat. My mood instantly lifted because the suffering was now "cheaper" than the freedom waiting for me.

Sleep and Smells: The Physical Reality of Daily Life on a Submarine

Does It Smell on a Submarine?

Yes, and it is a smell you never forget. It is called Amine.

Amine is the chemical used in the scrubbers to remove CO2 from the air so we can breathe. It has a distinct, funky, chemical-musty odor. After 24 hours onboard, your brain tunes it out due to olfactory fatigue. You don't smell it anymore.

The shock comes when you go home. You open your duffel bag, and the scent of Amine fills your entire house. That is the smell of deployment.

What is Hot Racking?

Space is the ultimate currency on a boat. While officers usually have their own racks (beds), junior enlisted sailors on Fast Attacks often have to "Hot Rack."

This is the practice where three sailors share two bunks. It is called "hot racking" for a literal reason: When you climb into the rack to sleep, the sheets are still warm from the guy who just got out to go on watch. It’s a jarring intimacy. You are crawling into a space the size of a coffin, smelling someone else's deodorant, trying to fall asleep instantly because you have watch in six hours.

Submarine Hierarchy: NUBs and Dolphins

Once you’ve figured out how to shower and sleep, the next shock is the social structure.

What is a NUB? If you walk onto a submarine for the first time, you are a NUB (Non-Useful Body). It sounds harsh, but it is accurate. Until you understand the systems—how to fight a fire, how to stop a flood, how the air gets scrubbed—you are a liability to the ship and everyone on it.

You are a ghost. You don't watch movies in the wardroom. You don't relax. You study.

The shift happens the day you pass your qualification board and pin on your Dolphins (Silver for Enlisted, Gold for Officers). In that moment, you transform from a liability to a brother. You are finally trusted to save the ship.

Do You Feel Storms Underwater?

People think we are immune to the weather. We aren't. While we escape the crashing waves, during a bad storm, you can feel the "sea state" hundreds of feet down.

We also do "Angles and Dangles"—drills where we take the ship to steep angles (30 to 40 degrees) to check "stowage for sea." If you didn't secure your gear, this is when you find out. You'll hear a crash, and then feel the shame of everyone knowing it was your gear that fell.

The "So What" for Leaders

Why does this matter to anyone who isn't a sailor?

Because the "Happiness Factor" applies to everything. Whether you are building AI infrastructure or managing a crisis, your team is constantly doing mental math: Is the struggle worth the reward?

At Northstar Enterprise + Defense, we apply this same rigor to critical infrastructure. We don't just build data centers; we build systems that survive contact with reality. The discipline required to live in a steel tube—the precise attention to valves, the reliance on procedure, and the ability to endure isolation—is the exact same discipline required to deploy modular data centers in austere environments.

It’s not the movies. It’s sweat, Amine, bad coffee, and a crew that trusts each other when the alarm sounds.

FAQ: Common Questions About Submarine Life

Frequently Asked Questions (FAQ)

Who is Tony Grayson?

Tony Grayson is President & General Manager of Northstar Enterprise + Defense, former Commanding Officer of USS Providence (SSN-719), and recipient of the Vice Admiral James Bond Stockdale Award for Inspirational Leadership. He served 21 years in the U.S. Navy submarine force.

What qualifies Tony Grayson to write about submarine life?

Tony Grayson commanded USS Providence (SSN-719) and served 21 years in the U.S. Navy submarine force. He earned his Dolphins, completed multiple deployments, and received the Stockdale Award. He lived the Silent Service firsthand.

What does a submarine smell like?

Submarines have a distinctive smell dominated by Amine—the chemical monoethanolamine (MEA) used in scrubbers to remove CO2 from the air so crews can breathe. This technology has been used in nuclear submarines since the late 1950s. It's a sweet, somewhat nauseating chemical-musty odor that gets into everything: your clothes, your skin, your hair. After 24 hours on board, your brain tunes it out due to olfactory fatigue. You stop noticing it—but when you come home on leave, everyone around you can smell it immediately. You open your duffel bag and the scent of Amine fills your entire house. That is the smell of deployment.

What is 'hot racking' on a submarine?

Hot racking is when multiple submariners share the same bunk in shifts because there are more crew than bunks on Fast Attack submarines. When you finish your watch and go to sleep, someone else wakes up and takes your spot on watch—and when they're done, they come back and sleep in the same bunk you just vacated. The rack is literally still warm from the previous occupant. It's called "hot racking" for this literal reason. You're crawling into a coffin-sized space, smelling someone else's deodorant, trying to fall asleep instantly because you have a watch in six or eight hours. Officers usually have their own racks, but junior enlisted sailors on Fast Attacks routinely share bunks with two or three others.

How long are submarine deployments?

Fast Attack submarine (SSN) deployments typically last 6-7 months, with the boat spending 2-3 months continuously underwater during certain operational phases. Ballistic missile submarines (SSBNs) operate on 90-day patrols, alternating between two crews (Blue and Gold) so the boat is always at sea maintaining nuclear deterrence. The crews swap in port, and while one crew deploys, the other trains and maintains readiness. During these deployments, submariners have no access to sunlight, news, or real-time communication with family.

Do submarines have Wi-Fi or internet?

No. When a submarine is submerged, physics prevents radio waves from penetrating seawater beyond a few feet. We have no internet, no social media, and no news from the outside world. Submariners can receive limited text-only emails (often called "Sailor Mail" or "Familygrams") when the ship comes to periscope depth to raise an antenna, but these messages are screened by the crew and often delayed. There is no way to send messages back in real-time. This communication blackout is one of the defining features of submarine life—you are completely isolated from the world for months.

What do submariners eat?

There is a myth that submariners have the "best food in the Navy." The truth is: we have the best food... for the first two weeks. That is how long the fresh produce (lettuce, milk, tomatoes) lasts before it runs out. Once the fresh food is gone, we switch to canned and frozen goods for the rest of the deployment. The submarine galley operates 24/7 to feed three watch sections. We do have fresh bread, however, because we bake it onboard daily—the smell of fresh bread is one of the few pleasant aromas competing with Amine. Submarines receive extra food funding compared to surface ships because morale matters when you're trapped underwater for months. Read more about submarine food logistics here.

Can you smoke or vape on a submarine?

No. Smoking has been banned below decks on U.S. Navy submarines since December 31, 2010. Because submarines recycle their own air in a closed-loop system, smoke is a contaminant that the CO2 scrubbers and air purification systems struggle to remove. Secondhand smoke affects the health of the entire non-smoking crew in the confined environment. Before the ban, designated smoking areas existed, but the Navy determined the health and operational risks outweighed any morale benefit. Vaping is also prohibited for the same air quality reasons.

How deep can a submarine go?

The exact operating and crush depths of U.S. Navy submarines are classified. However, the Navy publicly states that American submarines operate at depths "greater than 400 feet." Los Angeles-class submarines like the USS Providence (SSN-719) are generally understood to have test depths exceeding 600 feet. The pressure at these depths is immense—approximately 30 times atmospheric pressure at 1,000 feet—which is why submarines have no windows and why every system must be engineered for this extreme environment.

Do you see fish through the windows?

Submarines do not have windows. The pressure at 400+ feet would shatter any glass strong enough to be practical. We navigate entirely by Sonar, charts, and inertial navigation systems. The only time we "see" outside is through the periscope, and that is only when we are just a few feet below the surface at periscope depth. Below periscope depth, submariners operate in a world of sound, not sight—Sonar operators listen to the ocean and translate acoustic signatures into tactical information. It's a completely different sensory experience from surface ships.

What is the 'Happiness Factor' on a submarine?

The Happiness Factor is a mental model submariners use to stay sane during long deployments. It's calculated as: Happiness Factor = Days of Leave Approved ÷ Days Left on Mission. When this ratio exceeds 1.0, you've mathematically "beaten the boat"—the reward waiting for you now outweighs the remaining suffering. For example: 21 days of leave approved divided by 18 days left underwater equals 1.17. The tipping point when this ratio crosses 1.0 produces an immediate mood lift. It transforms abstract endurance into concrete progress. Survival isn't just about grit; it's about calculating leverage. This kind of morale math applies to any high-stress, long-duration challenge—whether you're building AI infrastructure or commanding a submarine.

What is a NUB on a submarine and how do you earn your Dolphins?

A NUB is a "Non-Useful Body"—anyone who walks onto a submarine for the first time without their qualification. Until you understand how to fight a fire, stop a flood, and how all the ship's systems work, you are a liability to everyone aboard. NUBs study constantly and don't relax until qualified. To earn your Dolphins (the Submarine Warfare Insignia), you must complete an extensive one-year qualification process covering virtually all submarine systems. You pass oral boards, demonstrate knowledge of damage control and casualty procedures, then the Commanding Officer reviews the recommendation. Enlisted sailors earn silver Dolphins; officers earn gold. The moment you pin on Dolphins, you transform from a liability into a trusted brother—finally qualified to save the ship.

What are 'Angles and Dangles' on a submarine?

Angles and Dangles is a drill where the submarine takes steep angles (30 to 40 degrees up or down) to verify that all gear is properly "stowed for sea." If you didn't secure your equipment, this is when you find out—you'll hear a crash, and feel the shame of everyone knowing it was your gear that fell. The drill tests both the ship's trim and the crew's attention to detail. While submarines escape the crashing waves on the surface, during a bad storm you can feel the "sea state" even hundreds of feet down. Angles and Dangles ensure the boat can operate safely at extreme angles during tactical maneuvering or emergencies.

What is the watch schedule on a submarine?

For nearly 45 years before 2015, submariners operated on 18-hour days: 6 hours on watch, 6 hours for maintenance and personal time, and 6 hours for sleep. This created constant "jet lag" as sleep times shifted by 6 hours each cycle. In 2015, Vice Admiral Michael Connor directed the submarine force to transition to 24-hour circadian rhythm-based schedules: 8 hours on watch, 8 hours for maintenance/personal time, and 8 hours of protected sleep. The USS Providence was among the first submarines to implement this change. Crews reported better sleep quality, less disorientation, and improved performance. The change was based on Naval Submarine Medical Research Laboratory studies proving the 18-hour schedule caused progressive sleep debt.

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Tony Grayson is a recognized Top 10 Data Center Influencer, a successful entrepreneur, and the President & General Manager of Northstar Enterprise + Defense.

A former U.S. Navy Submarine Commander and recipient of the prestigious VADM Stockdale Award, Tony is a leading authority on the convergence of nuclear energy, AI infrastructure, and national defense. His career is defined by building at scale: he led global infrastructure strategy as a Senior Vice President for AWS, Meta, and Oracle before founding and selling a top-10 modular data center company.

Today, he leads strategy and execution for critical defense programs and AI infrastructure, building AI factories and cloud regions that survive contact with reality.

Read more at: tonygraysonvet.com