Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange
Join us in building a kind, collaborative learning community via our updated Code of Conduct.

For questions about bodies of salt water large enough to sustain their own internal currents and do not drain to any larger body of water. Covers both currents, navigation, and ecology.

17
votes
9answers
4k views

Why build underwater outposts, rather than ocean-surface settlements?

Suppose we've colonized a planet with 99% of the surface area covered by oceans. It has submerged continental crusts, averaging 200-500m underwater, with the average depth of open ocean being 1000-...
1
vote
2answers
171 views

How long would it take oceans to evaporate if they stopped gaining water?

How long would it take for the oceans to evaporate if the following were true? They suddenly stopped gaining water through rain/rivers/etc., and External patterns (e.g. atmospheric humidity) were ...
2
votes
2answers
146 views

Marine Animals best suited for domestication?

What marine or brackish water animals would be best for domestication attempts by a semi-aquatic civilization? Bonus Points for those that get me pet/domesticated sharks!
7
votes
3answers
415 views

What is the maximum height for coral?

I have a type of coral that feeds off of bacteria that love bird feces (or something involving a bird species). It grows large rocky spires out of the water to create a habitat for birds. I need to ...
10
votes
6answers
290 views

Do moons determine the speeds at which tides move? Is there a limit to this speed?

I'm writing a short story that takes place on an imaginary planet that is 88% ocean. The planet has two moons and one continent that is regularly flooded under 500 to 1500 feet of water. The tides are ...
22
votes
12answers
9k views

Could a person scuba diving take off his air tank and use it to propel himself?

So, in my story, in a prelude to an epic aquatic fight scene, my main character gets chased by a great white shark. He swims as fast as he can but he can’t escape. Just to clarify, he’s wearing one of ...
18
votes
7answers
3k views

How do I maximize a planet's wave height (on average)?

Premise I am in the formation phase of a fictional world. I would like one of its notable characteristics to be extremely large waves. On Earth, most of our large waves are triggered by earthquakes, ...
-2
votes
3answers
87 views

How to save a person who has just fell down form an oceanic city? [closed]

So, my main characters, Bryan, Julia, and Logan have been visiting the city of Hydropolis, on the ocean planet of Aquatus V. The city overlooks the most beautiful sight under the sea, a 5,000 foot ...
15
votes
4answers
2k views

Could you actually make Sandy's Treedome in real life?

So, I have a question that focuses on a character from a show, Spongebob. Sandy Cheeks lives in a reverse aquarium under the sea in Bikini Bottom, in a dome that looks like this The Treedome is made ...
10
votes
3answers
3k views

Boats for really tall people

So I'm writing a book that takes place in an endless ocean with islands inhabited by many races, and I'm trying to come up with unique boat ideas for races; well I have most of them, but I would like ...
14
votes
7answers
2k views

Is it possible to detect or recognize mammals, fishes or any other sea creatures that swims in an ocean from a flying aircraft?

I am working on a story and I would like to know if it's possible to detect or recognize mammals, fishes or any other sea creatures that swims in an ocean from an aircraft with our current technology ...
3
votes
2answers
195 views

is it possible to detect submarines in a sea from an aircraft? if possible how will it be?

While working on my story, I just came up with this doubt. Is it possible to know or to detect something like a submarine in an ocean from an aircraft with our current technology? I mean to detect it ...
1
vote
0answers
63 views

Life on oceans above the sky [closed]

The Leidenfrost effect is a physical phenomenon in which a liquid, in near contact with a mass significantly hotter than the liquid's boiling point, produces an insulating vapor layer keeping that ...
-1
votes
2answers
97 views

What would be the best underwater environment to set up their civilization?

So, on the planet Oceanus, their exist a species, called the Crustaceanoids, who live in an aquatic environment. They are crustaceans, no duh, and are crab like animals. They are exceptionally ...
4
votes
4answers
115 views

Genetically altering soldiers to be capable of doing missions in an aquatic environment?

So, in the mid 25th century, humanity has become a space faring race, with about 10,000 planets under control of Earth. There are many different ecosystems on different planets, from normal ones, like ...
4
votes
9answers
270 views

How to sink a small island under the sea with 1960s tech?

So, on the planet of Qualia, a tiny island of the coast of Da’Tora called Saluk has disobeyed Tora VII the Slaughterers rule, which is never a good idea, as you can guess from the name. He stationed ...
8
votes
2answers
144 views

Is there anything wrong with my plate tectonics map?

Here is a map I just produced of the plate tectonics of a world I'm working on. Does anyone familiar with the subject see anything wrong with it? If you can differentiate between the penciled and the ...
3
votes
5answers
2k views

I need a way to transfer two men from a submarine to a sunken rocket [closed]

I need a way to get two men from the inside of a submarine to the inside of a sunken rocket 3000 feet under the water without killing the men flooding the rocket flooding the submarine Does anybody ...
0
votes
1answer
189 views

What could be the energy source of a sentient, supermassive biological entity on an ocean planet?

In exploring the xenobiology and design for an entity (Entity X) in my fictional universe, I wanted to raise the viability of an organism that is so massive, it is visible from the planet's upper ...
6
votes
2answers
197 views

How to keep this artificial water planet from evaporating or freezing?

Piggybacking on this question: Could soft matter infused with nano or pico sized magnets be used to clump together so that we could create environments with it? ...So we have a planet that has lower ...
20
votes
5answers
3k views

How deep can I make my underwater facility?

In my world I want to create a really deep underwater science facility to conduct weird and unethical experiments in. But I think to myself: How deep could I take such a building? Does it become ...
0
votes
0answers
67 views

Why would a world have a floating ocean [duplicate]

I'm imagining an expansive body of water that is suspended high above the ground. One that can sustain diverse ecosystems that take advantage of the water to air conditions. What natural or other ...
6
votes
1answer
166 views

Size and Effect of Ocean Tides on My World

I'm building a world that orbits close in to an M-Dwarf sun. I've figured out a bunch of the physical parameters of the world, I just can't quite get a solid handle on my tides. I know my tides will ...
10
votes
5answers
260 views

Would Floating Islands Dampen Waves on a Water World?

This is a water world with depths ranging from 2-3 kilometers deep up to vast shallows of only a few meters deep usually around volcanic islands, where there are coral islands not bigger than Hawaii's ...
33
votes
8answers
8k views

If there are water oceans, must there be oxygen in the atmosphere?

I am trying to create a planet that either has no oxygen in the air, or it has very little; i.e. not enough to sustain humans without the use of a breathing apparatus. Large portions of the planet (...
8
votes
2answers
651 views

Life in extremely low gravity water

Let's assume the planet has only one half the mass of the moon and is covered by shallow ocean. To eliminate water pressure at extreme depths, assume the ocean is also quite shallow, with a maximum ...
26
votes
5answers
5k views

How reflective is blood?

If you were on a raft in say, an ocean of blood, and it was very still, would you be able to see the stars of the night sky reflected in it? Would you be able to see your own reflection? How far down ...
0
votes
4answers
373 views

If all the water on earth were to be displaced into the atmosphere creating a water canopy, how thick would it be?

If the water on earth were displaced to surround the earth in the atmosphere to create a water canopy, how thick would that canopy be? I apologize I should have been more specific in my original ...
-1
votes
4answers
153 views

In a world 2x the size of earth would sentient aquatic life be more probable?

The idea is in a world with 2x the gravity (which follows from 2x the size), gravity would have less an impact in the oceans. Does that follow?
15
votes
8answers
5k views

What could cause the world to be almost completely submerged in water, naturally or man-made?

I'm trying to build a world that is almost completely water, but I couldn't come up with an explanation for WHY the world was like this. The world has the same gravity and atmosphere of Earth. It also ...
4
votes
4answers
227 views

Could a giant floating self-supporting city survive a thousand year voyage?

One of the main plots in my world is that a huge ship arrives in a strange group of isles. This ship a gigantic city that completely self-supports itself with farms, houses, gardens, parks, and even ...
7
votes
2answers
332 views

What are the conditions of an Earth-like, water-ball planet?

I'd like to explore some details on a so-called water-ball planet (i.e. a planet in the habitable zone of a sun, covered by a 100 km deep ocean). I am particularly interested where life could develop ...
61
votes
9answers
13k views

A 40km diameter alien saucer is floating 2km above the ocean for a long time. What are the effects on the sea ecosytem below?

Twenty years ago, a 40km diameter alien saucer came to Earth, and stopped 2km above the Atlantic ocean, somewhere near the midpoint between Casablanca, Morroco and Natal, Brazil but over international ...
-1
votes
5answers
199 views

Fleet defenses against massive creatures [closed]

In my fantasy world, humanity thrives on massive migratory fleets, moving in large numbers between the sparse islands. However, there are massive creatures that live in these places in between, ...
19
votes
10answers
3k views

How to keep a ship's crew healthy in a fantasy renaissance setting?

So, in the age of sail, there where hundreds of dangers lurking in ships, mostly in the form of sickness such as scurvy, and I'm looking for a way to have sailors in a similar technology level as ...
5
votes
4answers
488 views

Maximum Ship Size with Seasickness?

What is the maximum size a ship can become without negating the effects of waves to the point where seasickness is no longer a problem? The larger a ship becomes, the smaller the rocking effect waves ...
3
votes
2answers
184 views

Tides on a Water World

How would waves and tides work on a planet that is completely covered by Ocean? It would have: Oceans of Similar depth to Earth's Atmosphere extremely similar to Earth's Same type of star and ...
2
votes
5answers
269 views

What would happen to Earth if it were eclipsed for nearly 10 days?

What would be the major changes that could happen if Earth experienced a solar eclipse caused by a fictional planet for a minimum of 10 days? Mainly what would happen to the oceans and flora in such ...
18
votes
9answers
7k views

Could a jellyfish be bio-engineered to convert salt water into fresh water?

For my future world, I've decided that coastal cities need fresh water and there isn't enough of it to go around. I don't know how jellyfish work. Is it feasible or completely impossible for ...
3
votes
3answers
505 views

How can two planets merge into another, bigger planet?

In my universe, there are two ocean based planets floating in the space. I would like to merge them together with a realistic way. What event would cause the planets to merge into a bigger one? (Sorry ...
7
votes
9answers
654 views

Could a deep ocean creature use some kind of bacteria in its body as a way to generate oxygen?

I've been creating a world where most-to-all of its life resides in the deep ocean. For story purposes, I would like said creature to have lungs, but it is not necessary. Description of the Creature ...
5
votes
3answers
302 views

How would it feel to sail a Rocheworld ocean?

A couple days ago, I posted this question about what it would feel like to walk on a Rocheworld. For some background, a Rocheworld is a double planet system where the two planets are so close ...
3
votes
4answers
136 views

Is it possible for the ocean to be deprived of oxygen within 1 year?

I am wondering what kind of catastrophe could contribute to affecting the average dissolved oxygen level in the ocean to become less than 1 milligram per liter and as a result making 90% of the ocean ...
9
votes
2answers
685 views

Is a river running into sea while still being in a canyon possible?

I've been working on a story in which the main setting is basically a canyon around a river (like the Grand Canyon, I guess), but it's specifically where the river meets the sea, and it's still in ...
15
votes
6answers
2k views

A World with Freshwater Oceans?

Is it possible to have a Terran-like world where the seas and oceans do not have high levels of salt? Could, in fact, oceans and seas exist that were fresh-water? Excuse my ignorance. Assumptions: ...
38
votes
6answers
11k views

What if a portal is opened from the Mariana trench to the Sahara desert?

The first portal is placed at bottom-most point of the Mariana trench (the deepest part of any ocean, located in the western Pacific Ocean) and the second is placed in the Sahara desert in Africa at ...
6
votes
7answers
359 views

How Does Island Development Limit Population Growth?

So I'm wondering if a human civilization or a group of civilizations that evolved on an Earth-like planet comprised exclusively of islands no bigger than 500,000 km^2 (most of them would be smaller, ...
4
votes
2answers
219 views

Technological Progress of an Ocean Civilization

Would a humanoid civilization that evolved on an Earth-like planet with no mainland, but rather, only a series of volcanic islands (many of which are located near the equator and are dormant, thus ...
6
votes
3answers
613 views

Could Human Civilization Survive Hypercanes?

Alright, so I've been doing some research on hypercanes, which are, in short, theoretical hurricanes that may have ravaged Earth in its ancient past, when ocean temperatures were much higher (at least ...
6
votes
4answers
456 views

Breathability of Atmosphere on Ocean Planet

So I'm wondering if it would be possible for humans to live healthily on a largely Earth-like planet that was covered almost entirely in salt water. Landmasses would all be islands, with only a few ...