People have been trying to live under the sea – here’s how

Living underwater may seem like a sci-fi dream. And if humans can live in space, on the International Space Station, what’s to say we can’t live temporarily beneath the waves of our own planet? The ocean may be considered a hostile environment, but space is too. Researchers, experts and brave souls have been dedicating time and money to making this a reality – here's what's happened so far... (Picture: Getty)

The idea of living beneath the waves is not a new one. In the 1960s, French oceanographer Jacques Cousteau (pictured) accelerated the craze, and since then people have been building and spending limited amounts of time in underwater habitats. But why? Is there an eventual goal, or is it to just push the body and see how far we can go? (Picture: Getty)

Why have we been sending people underwater?

Water covers 71% of the Earth, and yet as of June 2024, just over 25% of the seafloor has been mapped. Living underwater will help us learn more about the marine life that’s there, as well as being able to study the ocean itself. But, like how we measure how humans react to living in space, we can also learn the effects of humans living underwater (Picture: Getty)

Can we live underwater?

There's a major issue with living underwater: we, as humans, are not adapted for it. We need oxygen and sunlight to thrive, and we’re no good when it comes to major changes in pressure. But since 2000, there has always been someone up in space, with the longest record held by cosmonaut Valeri Polyakov, who was up on the Mir space station for 437 days between 1994 and 1995. But a lot of the time, astronauts who come back to Earth have myriad of health issues such as reduced bone density and muscle atrophy. So, what about living underwater? (Picture: Getty)

Who has lived underwater?

In January, Rudiger Koch (pictured), a German aerospace engineer, spent 120 days living inside a capsule, which was submerged 11m (36ft) beneath the surface of the Caribbean Sea. When he surfaced, he reported no health concerns and celebrated with champagne and a cigar. The next longest time spent underwater is 100 days, by Dr Joseph Dituri, who spent time in a 9m-deep (30ft) lagoon in Florida, looking to understand the physical and psychological health effects of being underwater. After performing tests on himself every day, he found he was actually healthier – although 1cm (0.4 inches) smaller. His biological age had reduced by 10 years, and he reported better effects of sleep, his cholesterol levels and inflammation decreased, and his stem cell count, as well as his testosterone and performance on cognitive tests, increased (Picture: Getty)

Who is heading down there?

Of course, there are companies out there looking to explore life in the deep blue. UK startup Deep, funded by a single anonymous private investor, aims to build the first permanent human settlement on the ocean floor by 2027. Their plan is to create specially designed, house-sized submersibles which they call sentinels, which will have multiple bedrooms and a communal area. The idea is that these could house residents 80 metres below the ocean’s surface for up to 28 days at a time, although the hope is that this could one day be extended to months (Picture: Deep)

Nasa has also been sending people underwater since 2001, to the Aquarius Reef Base, located just off the coast of Florida. It sits around 20m below the surface, and scientists, engineers and prospective astronauts typically spend 7-14 days in the module. Nasa says the aquanauts, as they are known, experience some of the same challenges that they would on a distant asteroid, planet or moon. They said: ‘During NEEMO (Nasa Extreme Environment Mission Operations) missions, the aquanauts are able to simulate living on a spacecraft and test spacewalk techniques for future space missions. Working in space and underwater environments requires extensive planning and sophisticated equipment. The underwater condition has the additional benefit of allowing Nasa to 'weight' the aquanauts to simulate different gravity environments (Picture: Nasa/Mission Blue)