Okay, following my previous core question, after the apocalypse, one of my sets of survivors in this setting, the Usnay, managed to live in a fleet of ships for over a thousand years.

This is probably less of a direct question, and rather me making sure I have all my ducks in row here on the thoughts behind their survival, to ensure I'm not missing anything critical, and to have a bit of a reality check, I suppose.

Here are the facts:

  • They are living as a fleet of ships that are relics of the mid 21st century (2060). There are probably around sixty to eighty vessels total.

  • This includes their escort: three prototype navy destroyers that protect the civilian fleet from threats. These destroyers were state of the art at the time, with onboard cold fusion reactors, some form of magnetised armour plating, probably a deck mounted railgun or two, flak point defence, and stores of missiles and supercavitating (hypervelocity) torpedoes. In other words, enough to murder the crap out of anything looking at you funny.

  • The oldest of these destroyers is effectively the government centre and the flagship since it combines defence, order and early warning. Navigation orders come from the flagship as it analyses its records of the seas and uses its instruments to determine the best routes that avoid the roughest seas and disasters waiting to happen.

  • We can assume the first captain of this fleet was a pretty awesome person. After all, as the world broke down from nuclear war, they went around rescuing ships and coastal populations, and they planned for living on the sea for quite a while from the start.

  • They have converted a couple of Oil Tankers into Hydroponic or Aeroponic Farms (probably converting various tanks into rotary hydroponic facilities). I'm a little concerned about the engineering required in this conversion but hopefully its feasible. Given the kind of crops that grow best hydroponically, their main diet will be beans, tomatoes, cucumbers, strawberries, and leaf lettuces. Sounds like a decent salad! This is supplemented by fishing (at least some of the fleet will be fishing trawlers). Going by the figures in this question and assuming the absolute worst case scenarios, we can assume our two hydroponics tankers can support a fleet population of at least 10,000 people or so.

  • Many places actively catch rainwater with various devices and filter implements, but a couple of vessels may also be specialised in waste treatement and desalination. The fleet tends to stick to rainy climes where possible. Some processing of waste occurs where possible to save fresh water, but it is otherwise dumped into the sea.

  • Some vessels may bolt and tether to one another where this is convienient and appropriate; unbolting again if a storm is approaching. There are also freight barges that ship stuff and people between the various other vessels.

  • A converted Aircraft Carrier has effectively become a huge apartment block. Parts of planes were probably cannibalised to make structural components for homes here. This wasn't likely straight away, but rather after the long quiet set in and population density began to rise a bit. The aircraft carrier can also be assumed to be relatively new, probably also with its own fusion reactor. Its possible that its planes were actually drones if airforce development went/continued that way; though I doubt the successor to the F22/F35 was phased out instantly. Its also possible that a cruise ship or two are part of the fleet as alternate accomodations.

  • They have 'magic' for maintainence. This is, as noted in previous topics, the ability to interface with ambient nanomachines. We can assume that most generic rust and wear to the hulls can be fixed by nanomachines assuming they have access to some new materials occasionally.

  • Some trips to land are possible during this time; but are dangerous due to the demons that now inhabit the land. Since the demons have unpredictable abilities, engagement with them is on a purely last-resort basis for a ground crew (those few demons that might attempt to swim/fly out to the fleet would be annihilated by the destroyers, but coastal support for landers may be more difficult). Nevertheless, obtaining metal scrap and rare earths (and in earlier trips for the first century; canned foods), is possibily worthwhile enough to warrant it.

I guess my main questions here are:

A) How long would this conversion take? I'm assuming a couple of generations? This question has some good ideas about design (semi-submersibles, rafted components) but my plan assumes that is not possible to access any large manufacturing facilities for any significant length of time, and the skilled labour to use such facilities may be rare as well.

B) Given the available nano-maintainence, I assume the ships will be fine for this period (if rusty in all non-essential sections to preserve resources). Alot of the central crux of this plan assumes that most of the tech will last and last for a very long time. This topic's main answer says that the hulls will last many generations. But how long will modern ordnance stay live and usable? What about the computers? I'm also assuming that our Fusion reactors are Deuterium => Tritium and that we can indefinately sustain them using some process to extract it (2H) from seawater.

C) How would people evolve during this time (both physically and socially)? I know a couple thousand years isn't enough for drastic changes, but I'm assuming that people will become favoured towards being darker skinned. They will also steadily lose the concept of personal space. I have them currently on a loose pseudo-military hierarchy/meritocracy with the Sea-Marshal as the leader.

D) And of course, anything else I might have missed!

Other possible reference topics looked at include: Would it be possible for a city floating on water to exist? and What would be the ramifications of someone who has lived their entire life at sea?

  • $\begingroup$ europe.theoildrum.com/node/4558 $\endgroup$
    – John_H
    Commented Apr 23, 2015 at 17:49
  • 1
    $\begingroup$ Destroyers are pretty tiny ships to hold the staff a government needs, even a small one. In WWII the command ship of a flotilla was often a light cruiser to give room for the Admiral and staff. You might want some sort of yacht or cruise ship as the government 'building' $\endgroup$
    – Oldcat
    Commented Apr 23, 2015 at 18:01
  • $\begingroup$ @ John_H : That article is mostly around the infeasibility of accessing dissolved minerals, right? I was talking about creating Deuterium from seawater, which is pretty easy via Heavy Water (see en.wikipedia.org/wiki/Heavy_water#Production). $\endgroup$
    – eharper256
    Commented Apr 23, 2015 at 18:13
  • $\begingroup$ @ Oldcat : Hmm, there is that. I mainly went with destroyers since cruisers are already being phased out of most modern navies, and there aren't battleships anymore either. Perhaps I misworded that statement by calling it government centre: after all, you're right about capacity, but it wouldn't be the centre of government administration; that would probably be in the Carrier or Cruise Ship like you say. However, important decisions are still made in our destroyer and relayed to pen-pushers if it comes to that. $\endgroup$
    – eharper256
    Commented Apr 23, 2015 at 18:19
  • $\begingroup$ See "Shark Ship" by Cyril Kornbluth for a 1940s take on the concept. $\endgroup$
    – user535733
    Commented May 5, 2017 at 11:27

5 Answers 5


Very well thought out.

A) I'm sure the conversion from armored battle fleet to floating colony would take a while, but that would be ok because you wouldn't need it to be done in a hurry. It would just happen naturally in a lot of small steps as more people came on board and more structure was needed. Each step would be as fast as resources allowed, as people worked together to do it, but the steps might be spaced out a bit until need dictated.
For instance, in the early years raiding the shore for canned food and dry goods would be the major focus, with people starting farm prototypes in some of the carrier hangers. When the tankers are salvaged the farms would be moved over and expanded whenever parts were available to do it. The warships would have machine shops aboard, and additional tools would be salvaged whenever possible. Scrap could be obtained without going ashore by scavenging boats from marinas, as well as ones that drifted out to sea. Oil drilling platforms would be a wealth of scrap, parts, and tools. They would be stripped of tools and their positions would be mapped out, and the metal harvested one by one as the need arose.
You haven't said much about the demons (where they come from for instance), but I can see some small Caribbean islands being purged and turned into havens to store excess resources and possibly dry dock (to bring newly salvaged boats up to speed).

B) Not really sure, but it kind of depends on what a computer looks like in 2060. Same for other electronics. I propose that the nanomachines would be able to repair them as well.
Explosives are potentially a little more difficult, but with things like rail guns you need a lot fewer explosives. Military ordinance should be pretty stable, so probably a long time. Hopefully someone else can add to this :)

C) I don't think there would be much physical evolution over only a couple hundred years. Mutations from leftover radiation would not be beneficial and mostly fatal. If you had any changes, like skin darkening, it would because of mixed marriages, which there would likely be a lot of. Any kind of racism would be poison in that tight of a community and would have to be dealt with severely and swiftly. Plus the constant contact with other children would quickly teach them that there aren't any differences except skin color. Socially you're probably pretty spot on. People might lose a lot of modesty and personal space, but most likely it would change into a mental personal space, where you just wouldn't see/pay attention to things that didn't concern you. (I remember reading a book set in medieval Japan where rooms had paper walls, so basically no real privacy, so people just put up mental walls, not paying attention to stuff happening in other rooms.) People who still needed space would live/work on the smaller boats where there would be less crowding, or in the farm where you would have the impression of privacy. Extreme cases would be the scouts, leaving the fleet to look for supplies, and returning to the convoy when they needed to.

  • $\begingroup$ From prior question: "Miraculously, some surface humans did live on, but most were mutated by the radiation. Little did they know at the time, these survivals were entirely at the assistance of the remaining nanobots of the VIS, which had been unleashed upon the world en-masse by one of their original creators with a single command ‘Preserve as much life as you can!’. The nanobots truly, heroically tried their best to meet that demand, preserving life without being able to consider the consequences of such a poorly worded order. These ‘survivors’ would become the demons of the Usnay legends." $\endgroup$
    – eharper256
    Commented Apr 23, 2015 at 17:24
  • $\begingroup$ ^ Actually you gave me some suggestions for what they were in that previous question! Also, for C) we do have a couple of thousand years for the evolutionary aspect, not a couple of hundred. Still chump change in the grand scheme of things, I know, but thought I'd point it out. $\endgroup$
    – eharper256
    Commented Apr 23, 2015 at 17:39
  • $\begingroup$ @eharper256 Ah cool, I hadn't realized that the two questions were related. Glad it was some help. So the good news is that the demons won't respawn, so if they clear an island or two, and then park a ship nearby to keep demons from coming across the ocean, it could be a somewhat safe place to use. Raising animals for food, crops that don't do well hydroponicly, store scrap and tools, etc. Sorry I missed the thousand year part. In light of the nano thing you could maybe have some mutation on the boats? Could go either way, whatever works best. When you finish this let me know. Sounds fun. $\endgroup$
    – AndyD273
    Commented Apr 23, 2015 at 23:49
  • $\begingroup$ @AndyD273, out of curiosity, why would people lose a lot of modesty and personal space? $\endgroup$
    – Alendyias
    Commented Jan 25, 2021 at 22:54
  • $\begingroup$ @Alendyias So I'll have to see if I can recover the thinking I had 6 years ago, but you basically have a lot of people in tight quarters, so you're just not going to have much space to call your own, depending on how tight things get. If you have enough rooms that family units can get a private compartment, then great, but you're just as likely to get barracks style for a lot of people. It is based on the military. If you're single you might get a locker to put personal effects in, and a bunk of your own. If there are more people than bunks you might share one. That's the personal space part. $\endgroup$
    – AndyD273
    Commented Jan 26, 2021 at 2:39

But how long will modern ordnance stay live and usable? I’m an old Ammo Sgt/Ordnance solider here so my answer is based off that experience.

The shelf life of the ordinance depends upon the type.

Rail Gun: Indefinite. There is no explosive here to deteriorate. Keep the rust off and you're good. Flak Point Defence (assuming this is to stop incoming missiles?) Laser Type: Indefinite if you keep it running. (The U.S. Navy is currently experimenting with lasers) Explosive Rounds: 50-100 years. Depending on which plant it was produced in after the 60 year point a growing % will start going bad. You can often still shoot them, but 1 out of 1,000,000 will explode on you and 1 out of 100,000 won't fire at all. In another 10-20 years it might be 1 out of 100,000 will explode, and 1 out of 10,000 won't fire. Trained ordinance specialists can track which batches from which plants are going bad first and avoid them.

Missiles and Torpedo’s (Highly variable depending upon type) Dumb design: 40-60 years. Few missiles are dumb in the U.S. army ordinance (but there might be dumb torpedoes). However most cheap designs have a shelf life of 40-60 years. When these begin to fail they become less stable. They might explode in storage, or fail to explode. More expensive dumb designs have failsafes that keep them from exploding when they get old. Smart Design: 10 years unless you can upkeep guidance components. These have a very short life span. However it’s due to their guidance components. Once they go they can no longer target accurately. They won’t accidentally explode on you for a few more years though. We had to do monthly checks on our smart missiles optical components. Bombs and missiles from the air craft carrier supply would fall under the same smart/dumb category. These numbers are for general storage conditions. These would be sealed buildings that are not climate controlled or temperature controlled. For example, if you left your spare ordnance in shipping containers on one of the cargo ships. If you can keep the ordnance in a climate controlled environment their life spans will be longer, maybe even doubled. The air craft carrier would be the only vessel that could do this in bulk.

Then there is always the question of how old the ordinance was before it got to your fleet, and what kind of environment it was stored in.

I served approximately from 2000-2010. During this time I helped destroy a large amount of WWII ordnance and some WWI. It was around and still usable. Just remember, the longer it sits the more likely something will go wrong.

  • $\begingroup$ Wow, thanks for this; good to know some of the assumptions I went with are still correct, since I asked this question 2 years ago lol. $\endgroup$
    – eharper256
    Commented May 7, 2017 at 9:43
  • $\begingroup$ For the rail-gun, in the actual "state-of-the-art", it will not last indefinitly. Nowadays, when you shot, you remove matter (more than with regular powder gun) from the barrel with the friction of the shell. Maybe the munition, made out of solid metal, will last forever, but you will have to reshape, or even replace, the canon on a regular basis. Moreover, the capacitors used to generate the high power surge of the shot will deteriorate too. You already have the example of leaking/exploded capacitor in old electronic, from the 80's to 00's $\endgroup$
    – Cailloumax
    Commented Jun 18, 2019 at 15:23

C) How would people evolve during this time (both physically and socially)?

They would become excellent swimmers, foragers of the ocean, highly skilled at do it yourself jobs, navigation and reading the sea. I'd recommend reading up on the Bajau ethnic group as to how a people might evolve over time. Some of these people never set foot on land and live their entire life as nomads on small boats. They come together to form societies on the ocean. I've heard some of them can free dive for great lengths underwater on one breath of air. Living like this would be a lot freer and more independent than being stuck on big overcrowded vessels. Guardian article on the Bajau ethnic group


I can only take time to deal with A. at the moment. My background is engineer, blacksmith and metal worker. and a bit of hydroponics.

Q A) How long would this conversion take? .. my plan assumes that is not possible to access any large manufacturing facilities .. the skilled labour .. be rare as well.

Without skilled machinists, welders, and the really heavy equipment they would need to make proper, safe modifications on tankers, military vessels, and a carrier your people would only be able to jerry-rig .. flimsy construction that will get wiped away in the first heavy storm, even when inside the ship.

If I was in urgent need of living quarters for 10k plus people i would rather have a container ship than an aircraft carrier. With a plasma cutter, a few heavy duty stick welding machines it would take amateurs only weeks to create a floating apartment block.

an important question - the bigger the ship the more bunker fuel you need to run its engines. Maybe you get a nuclear carrier, but all the rest need a huge supply of fuel. Smaller ships need less but carry fewer people .. you need a detailed numeric analysis to find the sweet spot between fuel usage and capacity versus size of ship. Tugboats might modify the equation a bit, but in all cases you need a lot of bunker fuel.

Food Supply

They will not be able to clean the storage tanks of an oil tanker well enough to be safe to use for hydroponics. You would do much better with a bulk carrier with wall to wall retractable hatches to allow sunlight in during the day but protect the crops at night and in bad weather.

I did research into commercial hydroponics years back. Your folks are going to find it from hard to impossible to obtain the minerals/chemicals needed to create balanced nutrients for the different sorts of plants you want to grow. And you need a chemist with the specialist knowledge of plat nutrition to kill from burning the roots off the plants.

Good news - nearly any plant will grow in gravel-sand mediums as long as its roots stay damp enough to be able to absorb nutrients. And the water needs to be aerated to supply oxygen and filtered to keep it clean. Even root veg like carrots, potatoes, and beets do well if the medium is soft and sandy. Even corn can grow if you can feed it enough nitrogen. Special needs items like willow trees would be good to have a source of ASA, rubber trees .. if they can obtain roots, seeds and cuttings of useful plants they can grown them.

The problem with food crops is that you need to be thinking in tones per hectare. You need to have enough coming to harvest each month for all the mouths you need to feed. So if you need a hectare per month then you need 12 hectares total.

You can reduce floor area needed using vertical farm techniques, but you still need enough chemicals to provide 12 hectares with nutrient laden water, and you need a lot of water.

Lets say you need water 10 cm deep ( .1 metre) in each hectare, which is 10k sq metres, so you need 1000 sq metres of water, 100 litre, or, in total 12000 litres of water, and hundreds of kilos of chemicals to make the nutrient solutions .. and you need a diff solution for each type of plant

you have some challenges to overcome to make your story work .. but only if you need a high level of realism. Water World was an extravagant movie totally divorced from reality, except for the part about thugs being willing to follow the orders of the most vicious bully. I hope you do better with your floating survivors


"Magic" was the end of them

They rely on "magic" for maintenance. It doesn't seem to allow them to make new ships suited for their purposes. The result is that their own creative efforts are very crude and limited, while the all-powerful all-knowing machines around them retain a continual stasis.

We've read this story before, after a fashion. More than once, I'd say. In the static environment, dominated by outside forces, the humans degenerate into a form just barely capable of invoking the "magic" to fill their needs.


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