What It's Like to Live Underwater for 31 Days

Fabien Cousteau wants to change the way we think about the ocean. 

Fabien Cousteau outside Aquarius (Brian Hall/Mission 31)

Fabien Cousteau is on the ocean floor right now, and he's not coming up for air until July.

He can breathe down there, of course. There's an oxygen feed between the surface of the sea a few miles off the coast of the Florida Keys, where a support team hovers, and the underwater habitat Aquarius some 60 feet below, where Cousteau and five other people are living this month.

"We're six people crammed into a tube for 31 days, into something the size of a school bus." That's how Cousteau—yes, grandson of Jacques—described this experiment, dubbed "Mission 31," when we spoke a few months ago. The undersea lab is about 43 feet long and nine feet wide, which is minuscule compared with, for instance, a Royal Navy submarine. (Those are about 275 feet long and 30 feet wide, according to the BBC. U.S. Navy submarines have comparable dimensions.)

"Is it physiologically possible to live longer than 31 days underwater? Absolutely, it’s possible, technologically and physiologically," Cousteau told me. "Now, psychologically, that’s really up to the individual because of several factors—being separated from friends and family, the sun, fresh air, all those things." But Cousteau is happy to accept cramped quarters in exchange for unrivaled access to the most dreamlike environment on earth. "For me, the idea of going down to Aquarius for a month actually puts my mind at ease and gives me a sense of bliss."

Of course, Cousteau comes from a family of aquaphiles. His father Jean-Michel, his sister Céline, and cousins Philippe and Alexandra have all dedicated their lives to ocean exploration and advocacy. His famous grandfather Jacques-Yves Cousteau believed that one day humans would build and inhabit underwater cities. He built the first underwater habitat, called Conshelf I (short for "Continental Shelf Station"), in 1962. Then came Conshelf II and Conshelf III. Jacques made history by spending 30 days under the Red Sea aboard Conshelf II. Fabien Cousteau will, if all goes well, break his grandfather's record by one day—and by several meters. For the rest of us, the biggest difference this time around is that the entire adventure is being broadcast live. Cousteau has been telling reporters to think of the mission like "an underwater Truman Show."

He and his fellow aquanauts will communicate with the reporters and science teachers and students around the world every day via email and Skype. They plan to spend hours each day outside Aquarius, taking rocket-pack-assisted swims around the habitat and roving the continental shelf on motorbikes.

There is, of course, much to explore. Ocean scientists have made enormous strides in underwater research, but the 20th century's love affair with outer space means we know far more about the moon than we do about the sea floor. Cousteau sees Earth as a "little brown veneer," compared with the vastness of the sea—and he gets frustrated when people marvel at the Earth's oceans by saying that 70 percent of the planet is covered by water.

"[That's] talking about the world in a two-dimensional way, and the planet is three-dimensional," he said. "So if you’re talking about a three-dimensional system, the oceans represent 99 percent of our world's living space. And yet we’ve explored less than 5 percent of it."

This is something of a sore subject for ocean scientists, who point out that public funding for space exploration dwarfs the money that undersea researchers get. The United States government spends over 100 times more on space exploration than ocean exploration. Astronauts outnumber aquanauts by a similarly huge factor. But, Cousteau argues, the ocean has as much to do with the future of mankind as Mars does. "Space exploration is equally important, but if we don’t take care and understand our life support system first and foremost, then how can we imagine going beyond this little planet which sustains all life that we know?" (Or, as submarine designer Graham Hawkes puts it: "Your rockets are pointed in the wrong goddamn direction!")

Mission 31 is concerned with how the oceans are changing—namely, what we humans are doing to them. We've been using them as a carbon sink, a garbage dump, and simultaneously, a garden from which to harvest. Three broad subjects of study for the Mission 31 scientists are ocean acidification (as it relates to climate change), ocean pollution (with an emphasis on the effects of plastics), and declining biodiversity (attributed to overfishing). This is a bona fide research expedition, but it's also a publicity stunt. Cousteau wants to drum up enthusiasm for the sea, which helps explain why he's letting celebrities like rapper will.i.am and billionaire entrepreneur Richard Branson dive down to Aquarius for short 45-minute visits, and auctioning off similar experiences to the highest bidders. The idea, Cousteau says, is to spark the interest of a population of people who haven't previously gotten excited about the ocean—and to change the way they think about the planet.

"It’s really about engaging audiences young and old to dream, to aspire—the way we used to with the Apollo mission."

Aquanauts and astronauts: not so different. (Brian Hall/Mission 31; Warner Bros.)

Ocean exploration is part of what it means to be a human. Or, it ought to be, Cousteau says. He's stunned when I tell him I've never been Scuba diving. “Getting a diving certificate is easier than getting a driver’s license!” He learned how to do it when he was four years old.

The diving skill required for Mission 31 goes far beyond Scuba. What an aquanaut does is more extreme "saturation" diving, a technique pioneered by the U.S. Navy in the 1950s. "Most people think, 'Ah, you just go in, you kind of strap on a tank and jump in and have a good time'," Cousteau told Gear Patrol in April. "It’s like saying that jumping on a plane to go to California is the same thing as going to outer space and living on the space station. No."

During a Scuba dive, a person's blood and tissues become partially saturated with the gases he breathes through the tank he carries. The diver must return to the surface slowly, or decompress, to avoid getting the bends—the painful and sometimes lethal result of the absorbed gases getting released too quickly. Saturation diving works by letting the diver absorb a maximum and stable amount of breathing gas and then delaying the decompression process by housing the diver in a pressurized habitat like Aquarius. This is a major commitment because once you're saturated, you're stuck down there for a while. The decompression process at Aquarius today takes around 18 hours, according to Ben Hellwarth, who has written extensively on the history of saturation diving. "We’re committed to the bottom for days," Cousteau said. "And that has very real health considerations for us."

Indeed, being underwater for an extended period of time takes its toll. Cousteau says some divers begin to lose their sense of taste. Some feel euphoric, while others feel almost drunk—a level of fuzziness that can impair judgment. But Cousteau, it seems, is most concerned with the health of the ocean. "It is thanks to the health of our oceans in general that we exist," he said. "Whatever we do to the oceans we do to ourselves."