Underwater Civilizations Take 3

Read all of the debunked ideas here before posting!

I really hope I don’t get in trouble for this but:

  1. The forum is a bit slow and this will more than likely boost posts.
  2. Kiky is gone and he was one of the problems with this topic.
  3. I really want to talk about this topic just to talk not to try and have it added to the game unless we prove it is truly viable.

Since we have a bunch of new people who may or may not have looked at the old underwater civ stuff I will point out the main problems. You can’t have fire underwater to smelt metal, the creature would die of heat from hydrothermal vents. There are other as well but those are some of the main metallurgy ones.


Underwater Civilizations smelting like humans are not realistic enough. A civilization that can build underwater however is in my opinion a lot more likely. I’ve heard people speculate about building civilizations underwater in real life, so you will have to in some way be able to get on land before THAT type of smelting can occur.
If you could get a creature that can sustain very hot temperatures (think tardigrade protection level) why couldn’t they protect them self from hydro-thermal vents?
They could at least invent something that’s like a reverse scuba diving technology with that.

Second of all:

Well that’s the thing. The only reason the tardigrade is possible, is because it’s such a simple thing. It’s like those older phones (think Nokia), but as a microanimal: Very simple and can’t do a lot, but that’s why it’s really hard to destroy. Also, the tardigrade can only survive those extreme environments if it were to actively dry itself beforehand. It’ll basically enter a sort of hibernation. Then, the only way to wake it is by increasing the quality of the environments.
So even if you were to have a hyper-intelligent tardigrade-esque creature, if they were to activate their hibernation powers in order to survive themselves from the thermal vents, they wouldn’t be able to do anything, let alone forge anything


I think a more interesting idea is amphibious civilisations. Because they should be able to build cities underwater from the beginning (at least shallow water) and they should be able to advance all the way to the space stage.

I think because the society stages will be a strategy game it will be quite straightforward to allow underwater city building and to give a large bonus to underwater resource gathering to amphibious civs.

Sid Meier’s Alpha Centauri lets you build cities on the ocean and it’s awesome.


There is one problem what materiel would they use to build with that does not require metal working, because stone would be easily knocked over alone with any other primitive housing. I don’t see how they could build houses. I don’t think you could have an underwater civilization that has housing before metal working.

Remember that this is an alien world since there is no way for an intelligent species to develop far on Earth.
That being said, there could be a plant or form of large coral (Subnautica sized) that would provide the necessary levels of hard and protective material required for shelter.

an amphibious civilization is cool an idea i had is that if your civilization is amphibious you could develop underwater or amphibious vehicles faster than a land base civilization (also i thought some one said that hydrothermal vents couldn’t melt metal anyways) a way to actually smelt metal could be sometimes there could be a fissure in the ground leading to (or is close by) the core where it would be hot enough for metal melting how retrieval and survival will work i dont know but i would like an amphibious vehicle like Metal Gear RAY

I remember when ~sciocont outright handed out bans for anyone who made an underwater civ suggestion that had already been made. He was pretty adamant that the idea was impossible.

There should be a master list out there somewhere, perhaps?

I would also really like to have a list of all the collected arguments that have been made already.
And requiring people to read it before posting the same thing again.

I have a lot of time today (i am sick) so I can try to put together a list.

@TheNerdInTheCorner I think you could build underwater out of stone, what would knock it over, water currents? I think interestingly storms wouldn’t be a problem if you were quite far down, they would mostly blow over the top. Digging caves is another possibility.

I think there are some underwater structures from areas which have flooded.

Re reasons you can’t make an underwater CIV I think the main things are (I’m not an expert and open to other ideas or corrections):

You need metalworking to make an advanced civilisation.
You can’t make a regular furnace underwater.
You can’t really use hydrothermal verts as for one thing there’s not really enough of them to support a large civ. Another thing is they’re not hot enough, you need 700C+ to melt metals, to melt iron you need 1700C+.

In contrast to the approximately 2 °C (36 °F) ambient water temperature at these depths, water emerges from these vents at temperatures ranging from 60 °C (140 °F) up to as high as 464 °C (867 °F).

I don’t think anyones seriously suggested you could try to find lava etc. Anything above 407C would be really hard to handle as the water would start to vapourise (at least that’s what wikipedia says) which would make the are very dangerous.

Apparently you could use electroplating to make metal coated tools but I don’t think that’s going to get you far enough to build a rocket.


an idea i had was that perhaps you could find a fissure in the planets crust leading to the molten core area (or close to the area ) but the problem is that your creature would have to also survive the heat and needs a way to extract it though i once had a fish when i was younger that apparently can walk on land and breath (for a very very short period of time) with primitive lungs so a way to fix this could be that your creature can walk on land and perhaps hold its breath to try and quickly smelt with a furnace (pre placed from previous attempts)

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Yeah, I think he accepted that Stone Age was possible, but nothing beyond that because metallurgy was a too big of a roadblock.


Earlier I had offered the idea for a crustacean like creature with a silicon based shell that would protect it from heat. This heat resistance would allow it to withstand temperatures over 2,500 degrees F. The creature could go to these lava spots with no worry of dying and bring a mold with it or perhaps set up a basic forge there.

the problem is why would they? Remember that in something like this, progress needs to have a purpose. Fire was originally used as a way to scare of potential predators and cook food, and only later people would start using it for tools. It wasn’t even “made” originally, most likely for a long time a group would just have a fire that they’d keep fed, since if it died out they’d need to survive without fire until a forest fire happened or something that they could use to light something.
The creature you’re talking about would have almost no incentive to have fire, and creating fire wouldn’t be done either (Since they most likely wouldn’t know what uses fire would have, since it would be really difficult to keep a fire burning if you need to go underwater to breath every minute). Even if all of this would happen, forging something takes time. They’d need to constantly run back to the water to breathe, then run to the fire to smack the metal with a rock a couple time, after which they’ll have to breathe again.

Also @Steve how would a creature be able to survive temperatures of around 2500 degrees F, (1400 degrees C), purely because it has a silicon shell? Even if the shell wouldn’t melt at those temperatures, their inside wouldn’t be able to withstand it and they’d boil alive.


Silicon has a very low heat transfer rate which would allow them to be in extreme temperatures for a limited period of time, the less hot the longer. Also I said they could survive them not that they would since you don’t need that level of heat to melt early metal that is need.

I just looked on wikipedia and the melting point of silicon is: 1414 degrees celcius. So at those temperatures the shell would actually melt.

I’m still waiting for a paper with diagrams and accurate heat transfer calculations showing how you would melt metal and make it into an usable shape (that would advance your melting technology) without boiling alive or having the problem of not being able to retrieve your melted metal.

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Let us not forget that any circuits that an underwater civ might try to build would get fried, due to the water and all.

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I’m coming up with a plan for that but I am still finding information about electricity (interactions with water and properties of different material). However electricity is very far down the evolution of the species.

How about something similar to a water mil? wouldn’t enough water mils produce enough electricy. Using electricity the civilization could in theory make a place where you could heat metal up using electric energy to smelt? Would it ever get hot enough to do somthing like that?