You're a sailor on (in?) a brand-spanking-new Virginia-class nuclear submarine. You just set sail a couple of weeks ago, and were doing some routine exercises in the North Atlantic (about 500 miles north of Bermuda/500 miles east of New York), when total nuclear annihilation happened top-side - this is a total global nuclear apocalypse. All nuclear warheads are deployed, and nuclear power plants meltdown. Whoever orchestrated this was very skilled and thorough.

My basic question is: How feasible is survival aboard the submarine?

Some other thoughts/specific questions to guide your answers:

  • Assuming the warheads dropped and meltdowns occurred all on land, is the sub in any immediate danger underwater?
  • Does the fallout reach the middle of the ocean? If so, does this put the sub in direct danger? Is there a better place the submarine can move to avoid potential danger (e.g. the Arctic or the equator)?
  • The reactor on the sub can last for about 30 years. You can get fresh water by distilling ocean water. My best guess is that the hardest part of this scenario will be food. Let's say the sub has food aboard to last for about 3 months. With strict rationing we can eke out some more time. But eventually it will run out.
    • How do you obtain food? Can you catch fish from the submarine? I imagine you'd have to surface to do that...is that a big risk? Also, how will the longer-term ocean ecology be affected? Is fishing even feasible in the long run?
    • Another thought is to visit islands...small islands weren't targeted directly. You could try to visit survivors on these islands, but likely they are as dangerous as everything else.
  • $\begingroup$ apocalypse - as in end of the world - apocalypse? $\endgroup$ Commented Sep 30, 2015 at 15:18
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    $\begingroup$ Why would nuclear power plants meltdown when all nuclear warheads are deployed? $\endgroup$
    – gerrit
    Commented Oct 1, 2015 at 10:24
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    $\begingroup$ @gerrit Because skynet was hacked by the anti-nuclear eco-terrorist branch of anonymous and got it to detonate everything nuclear... (we don't talk about the explosions in the nuclear medicine departments of the hospitals as that's not good for our PR). $\endgroup$
    – MT0
    Commented Oct 1, 2015 at 12:20
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    $\begingroup$ Its worth noting that this is a planned scenario. All Royal Navy sub commanders have sealed orders in a safe which tells them what to do in the event of destruction of the government. en.wikipedia.org/wiki/Letters_of_last_resort $\endgroup$
    – Qwerky
    Commented Oct 1, 2015 at 12:53
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    $\begingroup$ imdb.com/title/tt0053137 --- but if you watch it then don't hate me. One of the few movies that gives me nightmares 30 years after. $\endgroup$
    – Rmano
    Commented Oct 1, 2015 at 17:53

9 Answers 9


There is a very good chance of survival

Surviving even a "total global nuclear apocalypse" is a lot easier than you think. Here's a good reference to look at. Some key points:

Within two weeks after an attack the occupants of most shelters could safely stop using them, or could work outside the shelters for an increasing number of hours each day.

Only a very small fraction of Hiroshima and Nagasaki citizens who survived radiation doses some of which were nearly fatal have suffered serious delayed effects.

Statements that the U.S. and the Soviet Union have the power to kill the world's population several times over are based on misleading calculations.

Non-propagandizing scientists recently have calculated that the climatic and other environmental effects of even an all-out nuclear war would be much less severe than the catastrophic effects repeatedly publicized.

And from someone who worked in a nuclear submarine's engine room

It's entirely likely [that] entering a nuclear facility in the wake of the apocalypse would expose you to dangerous levels of contamination. It's possible that the areas immediately surrounding them could have elevated levels of background radiation. It's unlikely that any effect would be noticed more than a few miles away.

If you can get to a reasonably good nuclear shelter, you have a good chance of surviving anything less than a direct strike. That's if you're on land!

The biggest advantage that a submarine crew has is that they can stay submerged for as long as their food supplies last. Also, water is an excellent blocker of radiation, so while they're underwater they are not in any danger at all. This leads to a huge overall advantage - after two months (until the food supplies run out) radioactive decay means that the overall level of radiation will have fallen significantly to easily survivable levels.

The biggest problem that the submarine crew will face is not knowing which areas were nuked and which weren't - this affects where they should go to try to find supplies. There's a good way to figure this out though - get in contact with the ISS. Having watched the entire mess unfold, the astronauts aboard the ISS will be able to direct the submarine to the areas that were hit by the fewest nukes.

Once they get to those areas, they should be able to figure out a way to integrate into whatever communities have survived, making long-term survival very likely.

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    $\begingroup$ @JustAnotherDotNetDev why would they bother? The ISS would be doomed anyway. $\endgroup$
    – Rob Watts
    Commented Sep 30, 2015 at 22:43
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    $\begingroup$ I've often said that the problem with a nuclear war is that it wouldn't kill enough people. Infastructure would be smashed, and too many survivors in suburbs and the like to be fed in the new situation. $\endgroup$
    – Oldcat
    Commented Oct 1, 2015 at 0:40
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    $\begingroup$ @txteclipse A: "I want your submarine!" B: "Do you know how to drive it?" A: "Uhhhh..." B: "Oh hey, we are recruiting. Are you interested?" $\endgroup$
    – Rob Watts
    Commented Oct 1, 2015 at 2:49
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    $\begingroup$ There's also going to be a whole lot of other submarines ... $\endgroup$ Commented Oct 1, 2015 at 6:47
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    $\begingroup$ @Michael Why wouldn't they help? $\endgroup$
    – Rob Watts
    Commented Oct 1, 2015 at 20:56
  1. No. The sub is out of immediate danger if it is far out in open waters, away from any mega port city.

  2. Yes, in the case of an ultimate nuclear doomsday, the radioactive effects would reach everywhere on earth through winds. It will take sometime though. I don't know how much, though. Depends on which ocean you are in and how many missiles hit which continent. It is sufficient to say that as long as most of your time is spent underwater, you are safe from direct radioactive effects. Poles would be the best place for immediate refuge but do not stay there for long as all atmospheric waste tends to accumulate on poles through snow storms. The next several dozen years would be a radioactive nightmare on poles.

  3. You can catch fish. The more benthic, the better. Radiation is less likely to reach deeper waters so eating deep water fish would be a better idea. However, notice that these would have much less nutritious value.

  4. Islands are safe only immediately (just like poles). Once winds distribute radioactive effects globally, nothing above the surface is safe for consumption. You should wait at least several years before you venture to any far Pacific or Mediterranean island.

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    $\begingroup$ That's not how nuclear submarines generate oxygen... $\endgroup$
    – Rob Watts
    Commented Sep 30, 2015 at 18:52
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    $\begingroup$ Agreed. I just checked out the oxygen production in new model subs and they produce their oxygen through electrolysis. Sodium superoxides were used far back during WW2 era submarines. $\endgroup$ Commented Sep 30, 2015 at 19:12
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    $\begingroup$ co2 scrubbers are much more important, you can get sick from co2 even if you have enough 02 in air. you need to get rid of co2, and thats what the scrubbers do. $\endgroup$
    – Jorge Aldo
    Commented Oct 5, 2015 at 20:48

Submarine would be in grave danger of being intercepted by an akula class attack submarine from the russian navy.

Ballistic submarines are part of the second strike capability of a nuclear power. They are able to counter-attack even if their airforce and land equivalents are destroyed in a counter-force first strike.

In order to be able to both protect own ballistic subs and destroy the enemies equivalents, attack submarines where developed. Russians have Akula class submarines for this task, while they use Typhoons as ballistic carriers (in the west the typhoons are erroneously called akulas).

When a submarine leaves friendly port for a patrol, there is a large chance that a enemy attack submarine follows his trail, in order to keep him on track all times. Russians done that, Americans too, and so on. So, if your virginia class submarine is out at the sea, you should be carefull if you are not being tracked by a akula class submarine, ready to take you out to prevent USA second strike capability. If you are near russian waters, you might be under tracking from their undersea microphone network and their kilo class diesel-electric submarines (wich are pretty hard to hear).

So, even if underwater submarines are not subjected to the dangers of nuclear explosions on the land, and their hull are protected from nuclear fallout (the sea is a very good shield), you still might be sunk.

Besides that point, your text assumes a 1960'esque scenario for that nuclear war. During that era, nuclear bombs where big to compensate for their lack of accuracy. They used what is usually called counter-value (targetting civilians). Modern day nuclear MIRV'ed warheads are low yield and very precise, and a rational opponent will use all the warheads they have to destroy enemy military structures and those industries directly related to defense, they wont simply strike cities because thats not a good strategy anymore. They will be used in counter-force mode.

After the first nuclear exchange, when the nuclear stockpiles are depleted and the economy ruined (besides the submarines second strike capability), there is no way to build new nuclear warheads, countries would fight a conventional, post-apocaliptic war, and if you use your bombs versus cities and leave the military structures and installations intact, you will fight a much stronger foe afterwards. So, the usual engagement mode is counter-force: Fire at the nuclear silos, airbases, anything that might stockpile nuclear warheads, them later fire at navy bases, cavalry, infantry battalions etc, everything that has military value. Thats the usual sequence for a decapitating first strike.

About the submarine at sea, you might try to contact other naval forces via satellite, try to rendezvous with friendly merchants etc. But you will be on a hard time, because a anti-merchant war will start to prevent supplies from reaching USA (and vice versa). War will be hot at the oceans. You might be able to join a surviving carrier battlegroup, or enter neutral waters to trade. But by all means your submarine is still a viable fighting machine and the first strike is not the end of the world nor will be the end of the war.


Survival of the initial event is effectively 100% as that's what submarines are designed to do. However, surviving out at sea is limited by the food supply on-board.


Just as on land, if you run out of breathable air, you die. A submarine has considerable capacity to operate for long durations. Creating oxygen is easy by using electricity to split water into hydrogen and oxygen. Removing carbon dioxide is done by lithium hydroxide. Heating the lithium hydroxide resets its ability to scrub.


Submarines carry desalination equipment so fresh water isn't an issue.


USN submarines often go out for six month missions so storing that much food isn't difficult. After that initial food supply, the submarine must return for resupply. This effectively limits the maximum time a submarine can stay out at sea.

Resurfacing will contaminate the sub to some degree and thus begin the slow march to radiation death.

  1. No, the submarines are designed to survive a MAD scenario (to perform a strike on the remaining targets), so immediately you'll be ok.

  2. Fallout may reach the center of the Atlantic ocean, if winds will allow it. Horse latitudes will probably be safe. But I don't think you'll have to worry about the fallout underwater. Remember what's spent nuclear fuel pools are made of. That's right, water, and these basins are far shallower than your maximum submerge depth.

  3. Why would you want it? You can go South America or Africa. Probably some South America country, like Chile (two research power plants) or Peru (the same). They're shielded by mountains and will have negligible internal fallout. As someone with the most advanced ship nearby, you may very well make a living as a mercenary king. After the global catastrophe someone will be itching to replay the War of the Pacific again.

  • $\begingroup$ at shallow waters, a nuclear submarine is easy target to diesel subs... $\endgroup$
    – Jorge Aldo
    Commented Oct 5, 2015 at 20:49

The war poses no threat to the submarine. You can stay out there until you run out of food.

At that point, though, you have a very big problem: You're coming up into a nuclear winter. The radiation levels have dropped to levels where you have an elevated cancer risk but it's not going to kill you outright. What will almost certainly kill you is the skies will be dark--nothing is growing. What are you going to eat?

Others have said to go fishing--but fishing for what? While you've been hiding out the fish have been starving because the algae they eat isn't growing.

  • $\begingroup$ Yeah that's what I was afraid of. Total ecology collapse $\endgroup$
    – Seth
    Commented Oct 1, 2015 at 1:00
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    $\begingroup$ Something I didn't know until I was researching my answer - Unsurvivable "nuclear winter" is a discredited theory $\endgroup$
    – Rob Watts
    Commented Oct 1, 2015 at 2:55
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    $\begingroup$ @RobWatts They're trying to promote their book. That page at least is talking about surviving the nuclear aspect, not the winter aspect. The nuclear aspect is definitely survivable with adequate preparation. $\endgroup$ Commented Oct 2, 2015 at 3:40
  • $\begingroup$ @LorenPechtel It's actually the full book. $\endgroup$
    – Rob Watts
    Commented Oct 2, 2015 at 4:22
  • $\begingroup$ @RobWatts I didn't notice it was the whole thing and not just a sample. That just confirms what I was saying--he's only addressing the radiation aspect, not the winter aspect. $\endgroup$ Commented Oct 2, 2015 at 4:56

As a long term food supply source if going ashore isn't an option, the only difference between fishing with dynamite and active sonar is that you'll eventually run out of dynamite.

OTOH breakdowns from inability to perform preventive maintenance will probably eliminate any subs hiding out in the ocean within a few years, either by forcing them ashore or causing their loss directly.


Lot of good info already, I won't repeat. Other than to say, I served (attack boats). And it is absolutely true that the world could end and you wouldn't know about it for several hours until pulling up to PD, if you were submerged, decent depth (which is pretty normal ops really).

But a few things to add:

  1. You have a large amount of radiation detectors (different types and ranges). As well as well-trained nuclear personnel. This would be important in scouting potential landing sites. Now the instruments and training is not designed for this scenario. But it could be repurposed easily and would be very useful. As compared to say a conventional destroyer or the like.

  2. A more general point, but you have a decent sized crew (115 or so). And they are well trained and overall highly intelligent. So I feel good about their ability to "adapt and overcome" to all aspects of the new scenario, not just dosimetry. This is a point that many people tied to shore establishments. But the USN has a pretty long history of operating thousands of miles from home. It drives a different mindset. Humans are assets--they can do damage control for instance. Something NASA, for instance, has never really internalized.

The one big disadvantage is a lack of small boats (that any destroyer has and has extensive experience with). So you'd be facing a little bit of precarious movement in life rafts, moving onto shore, when you get short of food.

  • $\begingroup$ Good first post, take our tour and read-up in the help center about how we work. If you fancy, please set-up a login and use the contact us button at the bottom of any page to get this post merged into your account. Welcome to worldbuilding. $\endgroup$ Commented May 12, 2021 at 19:38

Assuming the warheads dropped and meltdowns occurred all on land, is the sub in any immediate danger underwater?

Yes, mainly from other military submarines and/or naval forces, especially those designed to hunt submarines.

How do you obtain food?

If the surface air at sea is acceptably safe (some people say yes, others say no), then I would suggest trying to find cargo ships carrying food in refrigeration units. These have small crews and so may effectively have enough to feed your crew (and theirs) for a long time, and they may be large enough to build garden space on their decks. They would no doubt like your protection and be in no position to refuse you.

Can you catch fish from the submarine? I imagine you'd have to surface to do that...is that a big risk?

The size of the radiation risk depends on whom you ask, and also on what the situation is like with surviving hostile military forces.

Yes you'd need to surface and you'd want fishing gear... and/or you could find some fishing vessels and recruit them to fish for you - though they need fuel, unless you find fishing ships that use sails.

Finding or creating a way to grow vegetables would probably be an excellent idea. Researching edible sea plants too.

Also, how will the longer-term ocean ecology be affected? Is fishing even feasible in the long run?

Again it depends on whom you ask about the radiation. If fishing fleets are mostly out of operation and most humans are dead, I'd expect the fishing to get better and better.

Another thought is to visit islands...small islands weren't targeted directly. You could try to visit survivors on these islands, but likely they are as dangerous as everything else.

Again that would depend on what the actual post-apocalypse conditions are like, and the specifics of the island, and possibly what weapons your submarine has.

Also, the situation may evolve as time goes on and survivors reorganize. With governments destroyed, one might want to be cautious even about naval forces which would have been allied during the war, if they could consider you a threat or asset in some way. It depends on how many military submarines survived and how they remain (or newly) organize and behave in the new situation.

If the seas are relatively safe, then I'd recommend rounding up a fleet of civilian vessels to try to form a self-sustaining community, although since most other vessels probably run on fuel, that would pose problems. If the seas aren't safe, being on the winning side against surviving hostile naval forces might be the first task.

Oh, and of course, a terrible and probably unwise but true idea is one could check out how long the food you have can last, eat the shortest-lived stuff first, and then contemplate down-sizing the non-essential personnel aboard...


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