Don’t Hold Your Breath: Manned Undersea Exploration Is Dead

What's to come?
Sept. 17 2013 10:35 AM

Don’t Hold Your Breath

Why manned undersea exploration is dead.

A Sealab II aquanaut does an underwater job during a two-week stay at the habitat in 1965 off the coast of San Diego, Calif.
A Sealab II aquanaut does an underwater job during a two-week stay at the habitat in 1965 off the coast of San Diego.

U.S. Navy photo

Space flights have never been cheap or easy, but the human species has proved to have the right stuff when it comes to rocketing skyward. Despite the costs and complications, we—at least those of us in the celestial-minded United States—are still talking seriously about sending crews of men and women back to the moon, Mars, an asteroid, maybe even beyond.

But what ever happened to heading in the other direction, into the ocean depths? Half a century ago, it seemed only natural that we would be sending manned missions into the deep sea just as we were launching astronauts into space. Most of the world’s oceans, along with the terrain they cover, were and still are unseen and unexplored, and whatever we discover down there would very likely heighten our understanding of our very own home planet.

In that spirit, at the dawn of the Space Age, the U.S. Navy launched the Sealab program to figure out how to accommodate “aquanauts” on the ocean floor so they could live, work, and explore, like astronauts at a space station or on the moon. Nothing like this had ever been done, and not everyone in the Navy was convinced it was a good idea to try. Yet where matters of exploration are concerned, it counts to have people in the picture, weathering the elements, taking those historic first steps, planting that flag, and conveying to the rest of humanity the thrill of it all.

Yet the Sealab program, for all its successes during the 1960s, was allowed to (pardon me) sink. Since then, despite some noble, if relatively low-budget, efforts, it’s become clear: Where manned undersea ventures are concerned, we are not boldly going anywhere, or not nearly as boldly as once envisioned, anyway. History suggests that we have a habit of throwing in the towel when it comes to the glorious but perpetually underfunded and underappreciated field of manned sea exploration.

The kind of public interest and unbridled enthusiasm that has long sustained the space program and NASA’s multibillion-dollar budgets has never materialized for like-minded quests into the ocean. Last year’s near closure of the world’s only sea base was the latest case in point. If you can’t name this unique, American-run undersea outpost, you are not alone, and that’s at least part of the problem. It’s called the Aquarius Reef Base, and for the past two decades, this school-bus-sized structure has been operating a few miles south of the Florida Keys and a few fathoms below the surface.

From its beginning Aquarius has typically had to squeak by on less than $3 million a year, sometimes much less—a drop in the fiscal bucket by space program standards. (NASA’s estimated cost of a single space shuttle launch, for example, was $450 million.) Then last year the National Oceanic and Atmospheric Administration, which owns Aquarius, decided to pull the plug on the base. An organized effort to save Aquarius created an unusual surge in media and other attention—not major front-page headlines, to be sure, but there was at least a discernible spike.

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By the end of the year, the base had been spared, at least for the time being, though a long-term solution to keeping it open is still being worked out. The point is that for all the Champagne bubbles about saving Aquarius, it was soon clear that this was just a chapter like a lot of others in a decades-long history of false starts and unfulfilled dreams.

Around the same time the space program was getting off the ground, in the late 1950s and early 1960s, a revolution in manned undersea exploration was in the making. Most Earthlings weren’t aware of it, but U.S. Navy scientists and divers were quietly working to figure out whether there was a way around conventional diving limits, in terms of both depth and duration. At the time, it was considered extreme to dive much deeper than, say, 200 feet—and the deeper the dive, the shorter the stay. (We’re talking mere minutes.)

As is well-known, NASA had to do thorough animal and lab testing before subjecting human astronauts to gut-squishing G forces, weightlessness, and the whole laundry list of physical and psychological challenges that come with traveling into space. The list is at least as long for bodies exposed to the depths, pressures, darkness, cold, currents, and creatures of “inner space,” as some like to call the subaquatic realm. (Just ask Scott Carpenter, the Mercury astronaut and second American to orbit the Earth. He also took part in Sealab.)

What emerged from the Navy experiments was a game-changing method called “saturation diving,” for reasons having to do with how the gases you breathe are absorbed into your blood and tissues. “Sat diving” gave divers a way to acclimate to a particular depth and then stay indefinitely—for hours, days, and even weeks, provided they had some kind of shelter or base, with a heated, dry interior pressurized to match the pressure of the seawater outside. With this setup of equalized internal and external pressures, a hatch in the belly of an undersea base could remain open. Water would stop at the brim and the aquanauts living inside could don their dive gear and leave the base at any time of day or night, as they can at the Aquarius Reef Base. Marine researchers or anyone else could have the kind of unfettered access to the seabed that Jane Goodall had to the jungle. (There was just one thing: Immediate surfacing from a saturation dive at any substantial depth would kill you. A carefully orchestrated, gradual return to the surface is essential—one of the reasons it's sometimes best to stay inside the protective confines of a submarine or other such submersible craft.)

Among the first to pick up on the exploratory possibilities of saturation diving was Jacques-Yves Cousteau, who was already well-known as an ocean explorer and the co-developer of modern scuba. Having learned about the Navy experiments, Cousteau went ahead and staged some early demonstrations of sea dwelling, in 1962 and 1963. In the summer of 1964, the U.S. Navy put its concept of saturation diving to a deeper, more difficult test: A 40-foot-long, cigar-shaped steel habitat called Sealab I was placed nearly 200 feet below the surface off the coast of Bermuda. Four aquanauts were going to try to live and work for three weeks down there—an unprecedented undertaking.

This was followed up in 1965 by Sealab II, a larger, heavier, more refined habitat resembling a railway tank car, with room for 10 aquanauts at a time. (And, incidentally, there was a role for a Flipper-esque trained porpoise.) Sealab II was placed a little deeper than its predecessor and in more challenging waters (colder, darker) at a site off the coast of San Diego.