Technology: end of ww2 era (before de-armerment)

Population: ~2.5 billion

Location: current earth

Essentially, massive amounts of water have appeared, covering the entire earth. Humanity has roughly 1 year in order to adapt to survive this new flood, before all the land is either removed (mountains) or covered by water. Only rules are that it follows Newtonian physics and is reasonable for time period. All they have to do is make a sustainable civilization, that could survive for as long as necessary for humanity wants to. Solar power is available and since ww2 just ended, all those ships are also available.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – Monty Wild
    May 6, 2022 at 9:57
  • 1
    $\begingroup$ "something went wrong and earth’s solid terrain has been liquified" 🙄 Umm [holds up hand] that might have been us [shuffles feet and looks a little embarrassed] some malfunctioning self replicating nanobots originally designed to build flat road surfaces accidentally fell into our prototype experimental temporal displacement device in the now non existent future of 2417 and proceeded to turn the entire planet into a smooth spheroid, sorry about that, just one of those things, a freak accident, shouldn't happen again 🤗 $\endgroup$
    – Pelinore
    May 6, 2022 at 10:01
  • $\begingroup$ Noah: Am I a joke to you? Yeah my boat took 400 years to build, but with modern technology it would be way quicker. $\endgroup$
    – Murphy L.
    May 6, 2022 at 16:03

3 Answers 3


It sure an extinction level event, but let's investigate a little bit the capacities of making floating means, which they may need in this situation

I won't bother for looking ww2 productiin capacities, and will use fresh data from google for whatever I need, so scale down if you need it, anyway future looks grimm for them so it does not matter that much.

Production world wide, per year:

  • concrete - 4.4 billion tons
  • steel - 1.9 billion tons
  • electricity - 27 million GWh
  • natural gas - around 3000 billion cubic meters

There is no time to adjust production of energy, electricity etc - 1 year is too short, and best case scenario is to dump all there is in to making safe jakets.

Appropriate/considered technologies of that time:

  • concrete cargo ships - were build back then, lasts for quite long, sure has some cons but a legit war tech

  • zeppelins, and alike

  • usual iron ships, pontoons etc

  • cast basalt-gabbro-diabase ships pontoons - more like pontoons, more or less fictional application of this realy existing technoloy

Floating means design and required numbers:

Nothing complicated, proper ships take too long to build, so it more like smaller size pontoons, which then assemblied in some sort of island, floating platphorms - so more like square minecraft design, and more attencion is how much tonnage can be produced.

Assuming gradual decrease of production capacity, proportional to land mass dissapearance, which not so realistic, but if then numbers needs to be slashed in half. But real situation may be worse, or may be better(unlikely, but on the other hand war time efforts, then maybe) so that coefficient is not known, so let's assume best case - they do manage to produce those annual numbers, this or another way.

What is typical ratio of mass of a ship to cargo it can take - do not remember exact number but it around 1to6 to 1to8 ratios, will take lower number here, more robust crude construction, so 1 to 6.

  • materials used(mass) to payload it can carry - 1 to 6

  • To cast 1 tonne of stone it requires about 1MWh of electricity, steel is the same.

what do we have as result

Concrere pantoons - 4.4 * 6 = 26.4 billion ton

Steel pantoons - 1.9 * 6 = 9.6 billion tons

Cast stone pantoons - 27 * 6 = 162 billion tons

Zeppelins filled with NG - less than 1.5 billion tons displacement, and more like half or less of that number as payload


  • oil extraction is not counted and that about 6 times the electricity we generate, and considering that stone cast stuff may be the winner, it worth put max of oil energy as just a heat in to meltig and casting those stone pantoons. Not every stone is good for it, and it requires energy to extract as well, but usually it still cheaper than iron ore extractio.

  • ability to scrape cars and such for steel is not counted - and considering how much is produced yeach year, there should be a sizeable pile to recycle, but more or less this potencial is covered by stone castig.

what do we have at the end and what it gives to those guys.

Rounding up, they have about 200 billion tonn capacity, the for 10 billions it is about 20t per human, more than I was initially expecting

In therms of surface area, let's take 1m tick pantoons, it is too little, but to increase surface area, best case scenario - 20 million ha (or about 40 million acres)

So with 10% dietary need to be provided by plants grown ther(only necessities for vitamins and fiber), and 90% by fishing it may be sufficient for 400 million people

  • number may be more, or less. It like in assumption 2 people per ha, assuming yeilds one typically see 3-4t of food from ha won't be in place as problems of fertilisation, sea water moist and all kinds of problems. Google also isn't that much helpfull saying sustainable food growth requires 5 acrs per person, so as aquaponics setup is enough for 100 people per ha - so a big uncertanty here

  • aquaponics setups, and associated technologies should be a priority for reasons of high production yeilds, so as it is the way to keep microelements and other fertilising stuff in the system

If we take aquaponics system, with 100 people per ha, and it being just 10% of their food(initially), then we can get 20 billion people capacity. So surprisingly there are potencial scenarios when every one is taken, instead of 4% lottery ticket.

But that's an initial number not sure how sustainable is such a degree of fishing but if not, it can for sure prolong the struggle at least by few years. Where will be also natural decline of population (medical service is none, quality of food is different) so as other factors.

conclusion and perspectives

So there may be scenarios where most people are saved, at least for few more years, with expected significant decline of population, even if all are taken.

Technological competencies can be saved, as even for a less optimistic scenario population is high enough for that, but the main problem is that energy sources become inadecuate for implementing that theoretical knowledge, the problem can be solved, but it a long road.

Keeping stuff affloat probably a manageble activity and next 40-60 years it may be assumed they retain 70-80% of their fleet. Concrete ships did last for 60 years so, if they resist initial devastatin and struggles, they may have a chance to turn the table - they will have few decades at least.

So, in a reasonably optimistic scenario, humanity can retain its technological capacity, and not die out, even if probability of such scenario is low, but there is a road out.


Can't answer in comments due se broke site for me, js or what so do it this way

  • How do you continue to mine natural reources from the now submerged earth with WW2 technology? Solar is not an option. – @Trish

OP gave initial conditions, I filled the gaps in those conditions, and clearly stated them. I have such freedom of intrpreting the question because OP isn't dead set on any specific development, he just wants the end result - land mass is no more sticking above sea level.

And he gives 1 year to prepare, I guess it reasonable to assume some speed of sinking, and end of the year tip of everest makes T-100 I'll be back, but just under the water. At very least OP didn't state it sinks in 5minutes now, and his attempts to word the question clearly indicate it is a gradual process. So some portion of land is available until the last minute of the year.

I like that @Pelinore comment:

  • "something went wrong and earth’s solid terrain has been liquified" 🙄 Umm [holds up hand] that might have been us [shuffles feet and looks a little embarrassed] some malfunctioning self replicating nanobots originally designed to build flat road surfaces accidentally fell into our prototype experimental temporal displacement device in the now non existent future of 2417 and proceeded to turn the entire planet into a smooth spheroid, sorry about that, just one of those things, a freak accident, shouldn't happen again 🤗 – @Pelinore

I had similar scenario in mind, flattening the planet, and wrong depth is set, and wrong planet - in that sense I didn't had the problem may or may it not happen - if it can be done it may happen. But I decided to skip that part, as it not so relevant for the q.

My goal was to investigate what is a best case scenario, is there in such scenarion any best case and how it looks like, what are some numbers about it, what kind of size it is - is it enough for anything or not. I'm not interested to develop a story for the OP, but I interested to know is there a potencial for a story at all or not in such conditions. It turns out, that to contray to my initial expectations - there is a potencial for such setting, and that all I wanted to know.

And specifics in which way and how access to resources dissapear it all up to one who writes the story, I do not, I just say what can be done with certain resources, which are left or right of a number some one may have in his story.

To flesh the stuff with more aspects it quite a work, but in some sense it is typical doomsday and boostrapping combination. That bootstrapping aspect is what attracted me, and which potencial (is there some or none) I was evaluating.

I would like to comment on your answer as well, just that "nor does Newtonian physics allow it" - there is a potencial energy of high spots which can be used to flatten things, and more so processes of errosion do happen continiously it just slow - so it already happening meaning physics already allowed it, at much lower speed, and if there is an catalyst of the process, in my and Pelinore case those are nanomagic - it has the energy it needs for the process and physics isn't there to object the case.

  • $\begingroup$ How do you continue to mine natural reources from the now submerged earth with WW2 technology? Solar is not an option. $\endgroup$
    – Trish
    May 6, 2022 at 10:35

Neither will earth sink,...

melting off the polar ice caps only raises the water level by a few meters. That's the loss of regions like the Netherlands and some coasts, but with a year pre-loading, even those can be mitigated by heavy construction and earthworks.

...nor does Newtonian physics allow it,...

One of the core principles of Newtonian physics is the conservation of energy and conservation of mass. You can't get energy from nothing and mass can't go into the nowhere. Oh, and matter properties are only changeable by temperature or chemical reaction.

To get rid of all the land above the waterline, you'll need to alter the composition of the earth's crust so much that it can't uphold anything, and that would violate the conversation of mass. Or you need to melt earth without cooking off humanity, and fail there.

...nor would humanity survive on ships would it happen.

A single ship can hold some thousands of people. But a single ship can support exactly 0 people with agriculture out of the box. And even if stocked up with food to the brim, the ship can't support the people aboard for much longer than the fuel lasts. Yes, the limiting factor is that silly, at end of WW2 only mined on land, black stuff: fuel. Coal and Oil will limit the survival of the humans on the ships to a timeframe of weeks because that's when the bunkers run dry if you keep the engines running.

Random Cases in point: CV-17 Bunker Hill has a listed range of 14100 nautical miles. If running 24/7 at cruise speed of 20 knots, that's 29.375 days. Or about 4 weeks, one day, and 8 hours. Bismarck only had a listed range of 8900 miles at 19 knots, or about 19.5 days: 2 Weeks, 5 days, 12 hours.

Without any oiler, that's when the ship begins to die. Its ability to preserve food goes away and the crew is trapped in a metal box that they can't repair anymore, where they have no light inside, and in the deeper parts of the ship not even enough fresh air to breathe easily.

Oh, and preserving fuel by shutting off the engines or running it on the minimum is no solution, it only delays the inevitable: to be able to breathe in the lower decks of capital ships, the engine has to be running or land power lines supply the air ventilation systems. The moment the ships leave the harbor the last time they run on borrowed time, possibly about a year if you really stretch it thin.

Converting the Bunker Hill to a sailing farm would grant about 11970 m² on the flight deck. Let's round that to about 1 hectare or 2.5 acres. That's just enough to feed 3 people wich farm for wheat and grains and have some chicken. Not having the chicken doesn't help a lot either. Wih a little bit of tinkering, 4 people can be fed but no chicken or vegetable is grown. That is not even enough to keep the ship in good condition.

Fishing might be an even bigger problem: with no landmass and only deep ocean everywhere, there is no area where fish will reproduce or gather. There's no area where algae will grow and fish aggregate. In fact, many fish species will die out within the first months of the event, most of them those that we fish for food. However, some fish species will remain and might bolster the food as long as the fuel lasts, especially if dragging nets are used, especially with electric winches. But the moment the fuel is out so will the deep-sea fish supply dry up. Those will be plentiful weeks as the nets are still full... only to turn into horrible hunger.

Maybe farming some fish in nets and trying to supplement their diet will lessen the need, but in the long term, it is unsustainable without fuel.

So if we have our stranded aircraft carriers able to support tiny families of 3 or 4, that means that those families are the last generations there will be: the ships are too far from one another, unable to communicate, unable to repair as the ships rot under their ass (it takes a lot of electric power to keep ships in reserve from rusting and rotting), and see the people on them die before the hulks go under on their own or in a bad storm where someone forgot to close a door.

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    $\begingroup$ The question wasn't 'would rising sea levels cause a landless earth', it was 'this has happened, can they survive on boats', besides, melting caps, though the most plausible, aren't the only option for rising sea levels, you could slice off all the mountain peaks and high land and dump it into ocean chasms instead $\endgroup$
    – Pelinore
    May 6, 2022 at 10:39
  • $\begingroup$ @Pelinore The question specified "newtonian physics apply" which bans the premises, but the 3rd part is literally "it happened... and people will go extinct" $\endgroup$
    – Trish
    May 6, 2022 at 10:44
  • $\begingroup$ what's not Newtonian physics about bulldozing all the land above sea level into deep ocean chasms? 🤗 $\endgroup$
    – Pelinore
    May 6, 2022 at 10:46
  • $\begingroup$ "people will go extinct" Sure, but not straight away & not because the fuel runs out, it still floats, sails are possible, you can fish, fresh water is available by distillation, a tanker from the period provides deck space for at least a bit of agriculture what population it can support, if that's enough for maintenance, if not how long before it falls apart are all legitimate concerns . at a guess it should last several decades at least & potentially a hundred, maybe even hundreds, of years . and If they knew it would happen larger vessels than commonly in use then can be expected. $\endgroup$
    – Pelinore
    May 6, 2022 at 11:18
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    $\begingroup$ @Pelinore Bulldozing is possible, but not in the one year demanded. It takes a million years to use a million trucks to artificially erode the US. As for why fuel will kill them: nothing on those ships works without electricity. No steering, no air... you could support maybe a single family on the whole deck of the Bunker Hill if you farm there. $\endgroup$
    – Trish
    May 6, 2022 at 16:39

Edit: question was updated with new requirements so this answer is no longer valid.

I think it would be very difficult to find enough resources to build ships if there was no land on earth. Maybe you could make boats from whale skin and bones, but that would probably rot, right? Maybe you can make some kind of preservative...

Alternative: Aliens!

What went wrong

Scientific experiment with accelerators or atomic bomb weakened the dimensional barrier into another dimension. The world in the other dimension is a water world...

Maybe portals from the other dimension open up underwater and underground and water is flooding out, increasing the water level and flushing all the ground into the oceans ("liquefying the ground").

How to make ships and survive

Alien creatures come from the other dimension. The water is to deep so all materials come from killing the alien creatures. Maybe there are floating "trees" that can be made into sailing ships.

Old stuff

Some of the old metal ships and gunpowder weapons can still be used until they break down.


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