How different would water need to be for boats to be impossible?

Question

I mean changing the actual physics behind water (density, and other properties). How different would water need to be, to result in ships being impossible to build? (i.e. the ability to create transportation that floats on water, to be impossible to achieve).

Thanks :)

I think the biggest problem here is that altered water would be incompatible with life as we understand it. No life = no boat builders = no boats. So suspend disbelief about life, or suspend disbelief about boats. Consider some prohibitive organisms, instead. Krakens, killer sea-slimes, or hyper-corrosive bacteria that digest any boat within hours. — DWKraus, Apr 08 '22 at 16:56

score 8 · Answer 1 · answered Apr 08 '22 at 03:17

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In order to prevent the creation of a floating object that can be manned you would need the liquid to be less dense than any obtainable material on the planet. The idea of no solid matter being less dense than a liquid is... not easy to imagine.

Other options could be to increase the viscosity of the liquid such that it is near impossible to move across the surface. (Think of boat moving across a tar pit).

Lastly, you could make the liquid corrosive enough to destroy any solid matter. (Lake of very low Ph acid).

answered Apr 08 '22 at 03:17

Firebat

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thanks! what about if the density of liquid water was near the same as air? – Uzair Apr 08 '22 at 03:18
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If the density of the liquid was close to the density of air then very minor fluctuations in surface temperature would cause the liquid to boil off rapidly. The liquid being nearly as low density as the air would still not do anything about solids having a lower density, though it would make filling a bladder with air less effective as a boat. – Firebat Apr 08 '22 at 03:55
@Uzair if it was almost the same, then the first time there was a storm huge numbers of people would asphyxiate as "water" displaced the air in their homes. "Drowning" would be a terrifying threat in any low-lying area. On the upside, "airships" would be much easier to build, and much safer, too. – Starfish Prime Apr 08 '22 at 09:10
@Mathaddict did you mean to attach that comment to the original question, rather than an answer? – Starfish Prime Apr 08 '22 at 15:13
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Boats on less dense media aren't impossible, they just need to be bigger to displace a volume of fluid equal to their weight - water is already far less dense than metal shipbuilding material. Viscosity alone also may not affect ability to move through a fluid - although a viscous fluid has more drag, it's easier to push off of to propel yourself forward. Sailing boats would be less effective, but rowboats and motorboats should behave similarly. See https://www.nature.com/articles/news040920-2 – Nuclear Hoagie Apr 08 '22 at 20:04

score 2 · Answer 2 · answered Apr 08 '22 at 19:26

You will increase the density of the atmosphere to nearly that of water.

Xenon under pressure would be a good candidate. Pressurized xenon can be denser than water. Much discourse about the possibility here:

In what conditions could whales fly?

But for the boat: a boat floats because the volume of air in the boat plus the volume of boat matter weighs less than the displaced volume of water. If the atmosphere was nearly equal in mass to the water then the addition of boat mass would make it too heavy and it would sink. If the atmosphere weighed more than the water it would sink down in the water - this is what Cody from Cody's Lab is showing in the linked idea: a bubble of water floating on pressurized xenon.

This way you don't need wacky physics. Regular physics will be fine.

- You could find a place with an interface between water and pressurized gas in a well stratified gas giant. How would a person live on a gas giant?

score 2 · Answer 3 · answered Apr 08 '22 at 19:49

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Methane in the water.

Methane bubbles can in theory make water temporarily lighter than air. This would cause most ships to sink rapidly.

You could have something similar happen with helium. Suppose lots of helium was trapped underground and for some unknown tectonic reasons massive amounts of it were being dumped into the water. These helium bubbles would make any ships sink.

Some 'boats' could still float of course, but they would be airships basically, and fairly expensive.

answered Apr 08 '22 at 19:49

Nepene Nep

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keeping that much gas in the water is basically impossibly, even if you replace the entire atmosphere. boats would be impossible ot build for all of a half hour. – John Apr 08 '22 at 20:27

score 1 · Answer 4 · answered Apr 08 '22 at 23:09

Water is not a liquid

Your water is not a liquid. It is a dense gas. The sea looks like a big pool of fog. You can walk towards the ocean and keep walking downhill. You do not notice a sharp change. Only it smells different and you gradually lose sight of things behind you. And you start to asphyxiate.

No boat floats in this ocean. They sink to the bottom.

score 0 · Answer 5 · answered Apr 09 '22 at 01:25

Presence of lignin breaking microbes

You usually find these organisms in the gut of insects, specially termites.

If most water bodies have either free floating microbes that can break down lignin, or if there are aquatic animals able to eat wood due to hosting such microbes, then developing the technology for ships before a industrial revolution will be nearly impossible. Any wooden ships would be devoured faster than they can be built.

Boats may still be made out of clay or something else, but you will be limited to small, non-seafaring vessels.

How different would water need to be for boats to be impossible?

5 Answers5

Methane in the water.

Presence of lignin breaking microbes