Inside the 300-year-long project to live underwater

Living underwater does come with significant problems, which is the reason why doing so to date has not proved successful. A handful of limited experiments precede it, with one attempt by French ocean explorer Jacques Cousteau to build an underwater station in the 1960s achieving some success, albeit at only 32ft deep. The US Navy also built the Sealab habitat in the Sixties, but funding was ultimately lost to be ploughed into the space race.

Key problems include low temperatures, high pressure and corrosion. The change in gases – such as an increase in helium – also breaks electrical equipment and makes people feel cold; the Sentinel habitat will need to be heated to 32 degrees to make it feel like 21. High humidity also creates the potential for a lot of bacteria build-up, with people at risk of getting skin and ear infections, and the pressure also means people’s taste buds stop working – so those on the Sentinel will be eating food loaded with spices. 

Goddard adds: “What we are looking to achieve is not an individual placement at an individual site. It’s about getting the right people under the ocean, and opening it up to non-specialists.

“The ultimate aim is that there will be hundreds of these deployed around the world. This is not a case of scratching an itch. This is what the planet needs, and what our ocean needs.”

It is needed not to house an expanding global population, according to Deep, but because the ocean is the planet’s final frontier.

Research by the National Geographic Society shows more than 80 per cent of the ocean has never been mapped or explored – which means we know less about it than we do the surface of the moon. Some 90 per cent of ocean species are believed to be still undiscovered; so far, we know of around 226,000 ocean species, but some scientists estimate that there could be a few million more. 

The depth that the Sentinel can reach – 656ft (200m) – is the deepest point at which sunlight penetrates the ocean, and where 90 per cent of marine species are found. But climate change, overfishing and ocean acidification are causing unprecedented changes to oceans, which, Deep says, need to be urgently understood. 

“The sentinel can go to 200m, but the sweet spot will be 50 or 60 metres down, where it will be lighter,” says Goddard.