The Diving Bell and the Exoskeleton: An Excursion into the Depths

If you want to dive deep, there are only two ways: transform your body or wear armor.

A search for a photo of a miniature submarine took me to a government website, and as I browsed the tiny thumbnails, I saw something better than a tiny sub in the water. I found a picture of a man standing on the bottom of the ocean. And I've been staring at it for a week.

In the image, we see a yellow exoskeleton with two grey tubey arms ending in pincers. A clear cupola forms the top. What appears to be a thruster attaches to one side, and perhaps the other. Inside, a man in a t-shirt looks out into the water with a flashlight.

The imagination spins wildly through science fiction scenarios—Forbidden PlanetBioshock!— landing on this one: a colony of undersea humans repurpose dopey robots from the pre-electronics age into mech suits for the ocean floor. 

As it turns out, this is not so far from the truth.

The people who made them are underwater inventors who tested their contraptions with their own bodies, and their stories are crazy.

And I'll tell you this much about who uses them: Navy submarine rescue squads, oil companies, and a new scientific expedition to study bioluminescent life. 

But before we get there, we're going to have to learn a little bit about the realities of the subsea.

* * * 

Deep diving is one of the most preposterous activities in which humans engage. Put it this way: diving below a few hundred feet into the ocean pushes the human body farther outside its natural limits and tolerances than walking in space.

But unlike space, the oceans contain resources that firms can profitably extract. In the 1960s, oil companies began drilling offshore in the North Sea, Gulf Coast, and in the water near California. Building drilling rigs requires divers. So, a lot more people have ventured below than have gone on orbit. The divers do the dirty work: welding, laying foundations, inspecting pipes

These aren't just guys in scuba gear. Recreational scuba divers stop at 100 or 150 feet of depth. Beyond that range, the human body can't function normally.

First, there is the bends. As people descend in the water, gases (mostly nitrogen) diffuse into their tissues. That's fine, but as they ascend, and the gas comes back out of their blood and ligaments and liver and muscles, it can form bubbles if the divers come up too quickly. Those bubbles can cause pain and serious injury if they end up in the wrong place. 

People learned that they have to ascend slowly, stopping for long periods of time at set depths. Decompressing slowly is best, and the longer and deeper the dive, the longer it takes. We're talking a day, a week, or more in some cases to fully decompress. 

Two other physiological problems emerge as the divers sink into the darkness. First, the nitrogen makes them feel high.  "You end up feeling basically drunk," one diver told me. "In warm clear water, it can be euphoric. In dark cold water, it can be frightening, very frightening." Simply put: If one is breathing air, the brain begins to stop working below 130 feet. Second, oxygen becomes toxic at lower depths, too. It can cause symptoms from twitchiness to full-blown seizures. 

Both these problems can be mitigated by the use of more exotic gas mixes than air. Divers substitute helium for nitrogen and most of the oxygen. Generally speaking, they end up breathing a variant of heliox that's 90 percent helium and 10 percent oxygen. The pitch of the divers' voices bends upward, like teenagers inhaling the gas in a balloon. 

For serious commercial work, though, even these little human body hacks don't cut it. Those divers need to be able to work for hours and not spend days decompressing afterwards. 

So, a labor model called "saturation diving" became popular with the oil companies. For weeks, divers live and work at high pressure, keeping the gases in their tissues. They move from pressurized living quarters to a diving bell to the sea floor and back, where they're tended to by a support team that sends food and supplies in through pressure locks.

A diving bell used to carry divers to the wreckage of the USS Monitor (National Archives).

The oil companies contract with companies like CalDive, Helix Energy Solutions, and Oceaneering (remember that name). They train the divers, man the facilities, and acquire the jobs. 

The work is physically demanding, and the living conditions are cramped and weird. Nathaniel Rich described them in an essay last year in the New York Review of Books:

A saturation diving complex looks like a small space station. It comes in different sizes, accommodating six to twenty-four divers. A typical complex, which sits on the deck of a ship or an oil rig, has four main components. The first is the living chamber, which resembles a train’s sleeper car, or the berth of a submarine, and has double-decker cots with fire-retardant mattresses and a sitting area with a television screen. (Larger systems have two or even four separate living pods.) A camera—often referred to as “big brother”—peers through a porthole, observing the divers. Other portholes, covered with plexiglass, allow the marooned divers to glimpse the outside world.

Why would anyone work under these conditions? There's the challenge of it. The James Bond of it. The wildness of it.  

But really, the appeal is simple: "The deeper you dive, the more you get paid," Rich wrote. And the only way to go deep is to go saturated. It's been this way since the 1960s.

Saturation diving is, on the face of it, totally nuts. Some divers die: three in the North Sea in 1971 alone. Why were we sending these young men out there like this? There has to be some other way, right? 


* * *

The Tritonia suit, left, the precursor to modern atmospheric diving suits.

The year was 1935 and a boat sat bobbing in the sea south of Ireland at precisely 51° 25′ 0″ N8° 33′ 0″ W. Three hundred feet below lay the RMS Lusitania, a massive passenger ship sunk by a German U-boat in 1915. Sailors were gathered around two divers who were going to plunge into the ocean. 

The man on the right wears standard diving dress for the time. You'd probably recognize it, distilled in your mind from the undersea exploration montage sequences. It's a big, heavy suit with thick insulation. The helmet looks like a cannonball with a window cut out. The boots are cinched tightly. 

To the left of this diver stands an even more amazing artifact of the times, a hulking suit of cast magnesium. Armor for the sea! This is the Tritonia atmospheric diving suit (ADS). It is robotomorphic: in essence, a metal cylinder with jointed legs and arms. The arms end in pinchers, the legs in shoe-like platforms. The headpiece looks like a stolen submarine hatch. The suit is larger than any man.

The Tritonia is properly thought of as a human-shaped submarine. With a diver named Jim Jarrett inside, the suit was winched up and overboard. What the Tritonia gave up in mobility, it made up for in relative comfort. Jarrett fell through the water column dry and breathing a mix of gases that we'd just call air. He didn't need heliox or to deal with the effects of the pressure. The exploration was a success. He explored the sunken ship and lived to tell the story.

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Alexis C. Madrigal

Alexis Madrigal is the deputy editor of He's the author of Powering the Dream: The History and Promise of Green Technology. More

The New York Observer has called Madrigal "for all intents and purposes, the perfect modern reporter." He co-founded Longshot magazine, a high-speed media experiment that garnered attention from The New York Times, The Wall Street Journal, and the BBC. While at, he built Wired Science into one of the most popular blogs in the world. The site was nominated for best magazine blog by the MPA and best science website in the 2009 Webby Awards. He also co-founded Haiti ReWired, a groundbreaking community dedicated to the discussion of technology, infrastructure, and the future of Haiti.

He's spoken at Stanford, CalTech, Berkeley, SXSW, E3, and the National Renewable Energy Laboratory, and his writing was anthologized in Best Technology Writing 2010 (Yale University Press).

Madrigal is a visiting scholar at the University of California at Berkeley's Office for the History of Science and Technology. Born in Mexico City, he grew up in the exurbs north of Portland, Oregon, and now lives in Oakland.

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