Back in the 1930s, Swiss scientist August Piccard held records for both the highest altitude ever reached and the deepest ocean descent. In the last couple of years I’ve found myself retracing a similar journey, and while I may have travelled higher and deeper, I’ve done it from the comfort of my armchair. In books.
I was three when Neil Armstrong set foot on the Moon, so the Space Race was a part of the world in which I grew up. I had a childish interest in it, but in my late thirties that interest was rekindled after reading Andrew Smith’s Moondust. I’ve since used my fascination with the topic in my writing – not just the Apollo Quartet, but also in published and soon-to-be-published short stories. And I plan to continue doing so.
In 2010, I learnt it was the fiftieth anniversary of the first descent by human beings to Challenger Deep, the deepest part of the ocean on the planet, some 11,000 metres below the surface of the Pacific. In January 1960, Lieutenant Don Walsh, USN, and Jacques Piccard, son of Auguste Piccard, had reached the ocean-bottom in the bathyscaphe Trieste (which had also been designed and built by Auguste Piccard). I was surprised to discover that very little had been made of the two men’s achievement – in fact, I could find only a single book on the topic, Seven Miles Down, which I wrote about here. Contrast this with the huge numbers of books published in 2009 to celebrate the fortieth anniversary of the Apollo 11 Moon landing (such as these).

Space exploration has been in the public eye since 1957 and the launch of Sputnik. Underwater exploration – especially deep sea exploration – has not. Yet it’s actually just as fascinating a topic. While the “commute” is a great deal simpler and less expensive – you just sink – the environment at the bottom of the ocean is every bit as dangerous, if not more so, than space. It is an area in which great strides were made during the middle decades of the twentieth century, and in which all the various problems were solved by brute-force engineering… only for interest to fade away as it proved too difficult to keep human beings alive in that environment. Just like space exploration.
Recently, I’ve been reading about underwater exploration – partly as a result of my ongoing interest in the Trieste, but also because I’ve felt it’s a good subject for short fiction. Earlier this week, I finished Sealab by Ben Hellwarth, which is about the US Navy’s programme during the 1960s to build an underwater habitat. I also have a copy of Living and Working in the Sea by James W Miller and Ian G Koblick (recommended by Gavin Smith). And, of course, there’s plenty of material on the internet. Even so, underwater exploration is not as well documented as space exploration.
The idea of living at the bottom of the sea is not a new one. The best-known fictional example is likely Captain Nemo from Jules Verne’s Twenty Thousand Leagues Under the Sea, and that’s from 1870. There are, of course, plenty of difficulties to overcome – and not just the fact that human beings can’t breathe water. The deeper you go, the higher the pressure – one atmosphere for every ten metres of water. So at 610 m (2000 ft), that’s 61 atmospheres, or 61 kg per square centimetre. At such pressures, ordinary air is too dangerous to breathe. Not only is the partial pressure of oxygen increased to levels which can be toxic, but the nitrogen causes nitrogen narcosis, which presents as a form of debilitating drunkenness. Nitrogen also dissolves in the cells of the body, and returning to normal atmospheric pressure causes the gas to bubble out, often with fatal consequences – the bends. As a result, divers visiting below 60 m use a helium-oxygen mix. They must also decompress slowly to normal atmospheric pressure, a process that often takes longer than the period spent underwater.
One technique that has allowed greater depths to be reached is “saturation diving”. In this, the diver spends time before the dive in a sealed chamber in which the pressure is slowly increased – often over days – to the required level. If, for example, the diver will be operating at 200 m (650 ft), by the time they’ve completed compression, they will be breathing a helium-oxygen mix at 20 atmospheres, and the cells of their body will also be at that pressure. A sudden return to normal atmospheric pressure would be quite literally explosive.

Saturation diving is frighteningly dangerous. In 1962, Swiss physicist and diver Hannes Keller announced he would dive to the hitherto considered impossible depth of 305 m (1000 ft) using a secret mixture of breathing gases. In a diving bell, Atlantis, he and a British journalist, Peter Small, were lowered to the seabed off the coast of Santa Catalina Island, California. The plan was for Keller to place a Swiss and US flag on the seabed. Somehow, he managed to get his umbilical tangled in the flags as he returned to the bell, and once inside he passed out as the gas mixture had gone bad. Small had already blacked out. The bell was raised, and at 60 m (200 ft) support divers were sent down to assist. One of them never returned. Once the bell was on the ship, Keller revived, followed by Small two hours later; but Small then passed out again. Several hours later, Keller noticed that Small had stopped breathing. He tried to resuscitate him, to no avail. Once the bell’s atmosphere had reached two atmospheres – eight hours after it was originally sealed – it was opened and Small rushed to hospital, where he was pronounced dead. Keller had broken the deep-diving record, but at the cost of two lives.
Underwater exploration, and living, has been more successful in shallower waters, typically no more than 10 or 20 metres – depths at which it’s safe for a diver to head immediately for the surface. Jacques Cousteau operated his three Conshelf habitats in the Mediterranean between 1962 and 1965, before interest waned in the idea. US industrial Edwin Link, inventor of the flight simulator, experimented with his SPID, Submersible Portable Inflatable Dwelling, in which diver Robert Sténuit set a series of records, including spending 24 hours at 62 m (200 ft) in 1962. The biggest such project, though it was initially run on a shoestring budget, was the US Navy’s Sealab, the brainchild of Commander George F Bond, who before joining the Navy had worked as a country doctor in an Appalachian village called, amazingly, Bat Cave. The Sealab programme comprised three habitats, each one larger and better-equipped than the preceding one, placed in progressively deeper water. Mercury astronaut Scott Carpenter joined the project on loan from NASA and spent thirty days in Sealab II. Sealab III, however, was plagued by technical problems, and ended in tragedy when a diver from the first team sent down to open up and then live in the habitat died of carbon dioxide poisoning on the ocean bottom at 185 m (610 ft).

The US Navy subsequently shut down the Sealab programme, but research into saturation diving continued in the private sector as oil companies began offshore drilling at deeper depths. They needed divers for seabed maintenance and repairs. A few other attempts were made at underwater habitats, but the idea of sustained underwater living, especially at depths of 200 m or more, was soon dropped. These days there are only a handful of underwater habitats in operation, and they all sit in shallow water – such Aquarius, which is in 20 m of water in the Florida Keys National Marine Sanctuary. Even commercial divers found it more efficient to stay aboard a ship in a sealed chamber at the required pressure, and travel to the seabed in a diving bell to work. These days, of course, much of the work done by saturation divers is instead done by remotely-operated vehicles, ROVs, which can operate much deeper and don’t require decompression.

While the US Navy may have canned Sealab, it didn’t abandon saturation diving. Instead, it mounted a secret mission to retrieve debris from Soviet missile tests from the floor of the Sea of Okhotsk. The US Navy then realised it could use saturation divers to place taps on Soviet military submarine cables some 120 m (400 ft) down in the same region. Operation Ivy Bells provided a lot of useful intelligence throughout the 1970s, before it was compromised by a traitor within the CIA in 1980.
During the 1970s, commercial diving companies and some navies had tried to extend the depth at which saturation divers could operate. Somewhere around the 310 m mark, however, divers begin to suffer from a variety of symptoms, even when using a helium-oxygen mix: lethargy, dizziness, shakes, vomiting, delusion and hallucinations. This was dubbed High Pressure Nervous Syndrome, HPNS, and it seemed like a natural limit had finally been reached. Eventually, it was discovered that by adding hydrogen, or a small amount of nitrogen, to the gas mix, HPNS could be avoided. Commercial saturation diving to 300 m became routine, and depths of around 600 m were found to be possible – in fact, to date the deepest dive ever recorded by human beings was to 534 m (1752 ft) by a team of commercial saturation divers in 1988. The deepest simulated dive – ie, in a compression chamber on land – was to 701 m (2300 ft) as part of a scientific exercise by a commercial diving company. The diver spent three hours at 70 atmospheres, and experienced only minor HPNS symptoms, a slight tremor. At present, it is believed human beings cannot survive deeper than 750 m to 1000 m.
Much like space exploration, science fiction typically glosses over the difficulties associated with living and working underwater – especially at depth. There have been numerous novels, films and even television series featuring underwater cities, but most seemed to take as given that some element of humanity has been engineered to survive underwater – even at depth. James Blish and Norman L Knight’s A Torrent of Faces features aquatic humans, as do, more recently, Alastair Reynolds’ Blue Remembered Earth and Peter Watts’ Rifters Trilogy. Actual diving, or realistic underwater habitats, seems more the province of techno-thrillers – much like accurate space exploration has been. Michael Crichton’s Sphere, for example, has all the elements of a good story – saturation diving, underwater habitat, and a mysterious alien spacecraft on the ocean bottom… but still manages to be a bad film. The Abyss is perhaps one of the best cinematic representations of deep sea diving, but the fluid-breathing diving suit is pure invention. Given the actual achievements made last century in saturation diving and underwater habitats, it seems a shame the topic is not more commonly used in science fiction.

Having said all that, depth is no obstacle when people remain in a one-atmosphere environment, as they do in a submarines, submersibles or atmospheric diving suits. Sf representations of these are far more common – from Frank Herbert’s The Dragon in the Sea to the seaQuest DSV television series. But that’s a topic for another post…