7 things you should know about the future of underwater cities

• The idea of humans living underwater may not be as crazy as you think.
• An idea once reserved for video games or science fiction, underwater cities may be a viable solution for humanity in the distant future.
• But what should we know before thinking about such a thing?

Would you pack your bags, clear your apartment, and move to an underwater paradise? Perhaps you might even dream of living in the fictional city of Atlantis. If it makes sense to go out and colonize Mars, the ocean is just as livable and is far closer to home. As you probably already know, the earth is 71% water. This could be prime real estate for future generations.

Living underwater does pose its fair shares of challenges, like cold temperatures, immense pressure, and a lack of oxygen. Not to mention, long-term underwater living can wreak havoc on your body. 

However, promising new horizons in underwater living could tackle these issues and have you or your future children living comfortably underwater in the coming years.

1. Underwater cities are not a new idea

Though not as frequently touted as some forms of space colonization, underwater living has titillated futurists since the beginning of the 20th century. However, the iconic ocean explorer Jacques Cousteau made this idea a reality, bringing it to fruition in the early 1960s.

For the uninitiated, Jacques Yves Cousteau was a French oceanographer, researcher, filmmaker, and undersea explorer who was primarily responsible for igniting the interest of the general public in the ocean and the eventual possibility of underwater cities.

Cousteau was so passionate about understanding and exploring the world's oceans that he created the famous Conshelf series of underwater habitats.

The structures allowed 'oceanauts' to live underwater for days or even weeks at a time. Each iteration of the shelters (Conshelf I, II, III) improved over time, eventually allowing six oceanauts to live underwater at 328 feet (100 meters) below the surface.

Cousteau’s efforts to colonize the ocean laid the foundation for the future of underwater cities. Conshelf sparked a craze, and in the late 60s and early 70s, more than 60 aquatic habitats were dotted across the seabeds, with names like Sealab, Hydrolab, Edalhab, Helgoland, Galathee, Tektite, Aquabulle, Hippocampe.

2. The depth of the colony affects everything

How humans breathe underwater and the depth of the structure are correlated, dictating how the structure should be created, and the mixture of air humans will need to live in their underwater city.

First and foremost, it appears that humans should not build colonies deeper than 1,000 feet (300 meters) and ideally at much shallower depths.

This is because the pressure at these depths would require very thick walls and lengthy periods of decompression when returning to the surface.

At these depths, humans need to take extra measures to ensure a healthy oxygen ratio to other gases in the air, as the body requires varying levels of air components when at pressure. Plants and artificial light could supply some oxygen, but depth, nitrogen, or helium would also be needed.

3. Food wouldn't be a problem in our underwater city

The good news is that living on the ocean floor could provide humans with ready access to seafood and sea plants. Some aquanauts live underwater and can partially support themselves via spearfishing, combined with canned and preserved foods. 

More traditional meals and fresh water could be transported through tunnel or hose systems connected to the surface.

4. Living underwater will give us a better understanding of the ocean

The idea of living underwater is of particular interest to scientists around the world, including marine biologists. Scientists and researchers have better maps of Mars than they do of Earth’s ocean floors. To this date, humans have only explored 3% of the ocean.

Living underwater could also help scientists better understand the planet and the evolution of life on Earth. Not to mention, many resources will still be discovered on the ocean floor.

Experts predict there could be an unquantifiable amount of minerals and metals that could be used to improve humanity and even help with the further construction of underwater cities.

5. There are architects already working on underwater city plans

Architects at the Shimizu Corporation have already designed a $26 billion project to create an underwater city. The Tokyo-based company said their project would allow thousands of humans to live comfortably underwater.

Though most of it is still just a concept, the Ocean Spiral City would sit below sea level off the coast of Tokyo. With its massive turbines, the city would power itself through waves, tides, and ocean currents, supporting those who lived on the structure.

The structure would support 5,000 people, including labs, schools, and beautiful residential areas. The underwater city could become a reality by around 2030.

6. The technology already exists… Sort of

Right now, humans can create underwater colonies supporting upwards of 100 people. As a biology professor at Stanford University Ian Koblick states, "There are no technological hurdles. You could do it today if you had the money and the need."

Constructed with steel, glass, and special cement, habitats are more likely to have a modular design than the more popular conception of a big underwater bubble or dome.

Structures could be added or subtracted from the underwater colony to help fit population needs. Larger underwater colonies are already feasible. A lack of interest, motivation, and funding keeps them from coming to fruition.

7. It could help preserve humanity

Hopefully, it won't get to this, but living underwater could help to save the human species in the case of a major apocalyptic event. Philip Pauley, founder of the London-based visual communications consultancy Pauley, has designed a self-sustaining habitat that could save 50-100 people during a disaster.

One way to combat the growing threat of war, limited resources, or global warming may come from moving populations underwater.

And that is your lot for today.

Would you live in an underwater city? You may not get the whole Rapture experience yet; however, restaurants and hotels are already popping up worldwide, allowing people to experience limited underwater living. It is probably more comfortable than living on Mars.