The group lands on a station in a hostile environment. Leaving that area requires oxygen tanks and special gear to cope with the pressure difference. A space station? Nah. A base built at the bottom of the sea. The US Navy was interested in such a base in the 1960s, and bases like this are the stuff of science fiction. But today, we see more space stations than underwater bases. Have you ever wondered why?
Deep diving is a tricky business. At a certain depth, the pressure forces a gas like nitrogen to spill out of your body. In itself, this is not a problem, but when you climb, it is a big problem. If the gas comes out all at the same time, you get bubbles, which can cause stress sickness, often called bends. The exact problems vary, but bending often causes severe joint pain, fatigue, or rash. Sometimes people die.
While you think of bending as a deep-sea diver’s problem, it can also happen on airplanes and in space. Anytime you go from high pressure to low pressure too quickly, you are subject to depression. Depending on what you are doing, there are different ways to reduce the problem. In diving, traditionally, you don’t just surface quickly.
You dive in, do your job, then head up, stopping at set points to let the pressure gradually equalize. Physics is a bear, though. If you stay for a long time at a given depth, you should reduce the time.
That means you quickly reach the point of diminishing returns. Let’s say you throw yourself into the ocean. You spend an hour working. Then you have to spend, say, eight hours gradually climbing up. That makes extended operations at significant depth ineffective.
George Bond thought about all this and had an interesting idea. It is true that, in general, the longer you sit down, the more gas your body holds. But it’s also true that, eventually, your muscles get full, and you can’t absorb anymore.
Saturation Diving
So the counterintelligence was not to send the diver down and back up again and again. Instead, you keep the diver under pressure for the entire job. Then, once, finally, you reduce. This is today known as saturation diving.
This leads to a new problem: If you plan to send a diver to the bottom of the ocean for a week, he can’t just stay in a wet suit the whole time. They need a place to eat, rest, and all the other things you need to do when you’re not working. They need a foundation.
It’s still not as easy as it might seem. There are problems with oxygen toxicity, trying to breathe under pressure, and other problems. But these are very solvable.
George Bond conducted an experiment under the working name “Genesis,” in which animals, and, eventually, humans were under great pressure for a long time. Around the same time, Edwin Link (a familiar name if you know about flight simulators) and the famous diver Jacques Cousteau were also trying to scuba dive for a long time.
As part of a larger plan, Link attempted to put one person into deep space a day, and Cousteau had a two-person crew at great depth.
The Navy decided to run some tests to see if Bond’s ideas would actually work. They began testing the “man of the sea” using three prototype “sealbs” that were much more ambitious than previous commercial designs.
Selab I
In 1964, off the coast of Bermuda, the Navy placed a pressure cylinder 192 feet down. The navel connected the living space to the top. You would think that the station would be filled with air, but the high pressure of nitrogen can cause other health problems, so, instead, divers have a mixture of helium and oxygen.
The group of four had to stay underwater for several weeks. However, an approaching typhoon cut their stay to just 11 days. Nevertheless, the experiment was successful.
It also presented a few problems. If you’ve ever inhaled helium, you know that it makes your voice hoarse, which can make it difficult to communicate with other people. More importantly, however, is that helium is a good conductor of heat. Divers get cold quickly in a helium-filled space.
You can see a video from the Navy in 1965 explaining the program below.
As a side note, former astronaut Scott Carpenter was going to be the fifth person on Sealab I, but a motorcycle accident in Bermuda knocked him off the list.
Lab II
In 1965, the Navy tried again with Sealab II off the coast of La Jolla in California at a depth of 200 meters. This time, Scott Carpenter made the trip.
Sealab II was more complex with demonstration tasks and a planned mission duration of up to 30 days. On long journeys like this, the same problems arise as you would on a space station. Carbon dioxide needs to be scrubbed, and oxygen levels need to be controlled. Moisture and corrosion are constant problems. Equipment noise affects people over time.
The new living quarters were twice as large as Sealab I. There were heaters, hot showers and refrigerators. The idea was to have a team traveling every 15 days, but Mbazi spent 30 days inside.
The Navy also tried training a bottlenose dolphin – Tuffy – to be an assistant to the crew with mixed results. While the campaign, as a whole, was a success, there were issues with staff feeling isolated and confined, as well as sleep problems due to noise and lights.
Famously, President Lyndon Johnson would speak to Carpenter after his 30-day stay and called while Carpenter was in a helium-filled pressure chamber. The confusion among the operators is hilarious, as you can see in the video below.
Sealab III
The next and final attempt to submerge a crew was Sealab III in 1969. At a depth of 600 meters – 200 feet above the normal planned depth – the Sealab III mission also used the Sealab II module, renewed and improved. Five groups of nine divers were scheduled to spend 12 days each in the area.
At such depths, problems multiply and the margins of error all but disappear. The Navy was already stretched thin in Vietnam, and Sealab III had a difficult time not only getting off the ground, but under the sea. The project is late and over budget. The work was sloppy, and corners were cut. When the shelter develops a helium leak, four divers volunteer to repair it on site, but fail in their first attempt.
The second attempt had the divers take amphetamines to stay awake, which predictably went wrong. The diver, Berry Cannon, died. At the time, an improper setting of his rebreather was discovered, although modern investigations speculate that he may have been electrocuted. Either way, it was enough to end the show. The Navy abandoned the program and focused on other undersea programs, such as submarines. If there are bases under the sea, they are too secret for us to know about.
You can see a Navy video showing Sealab III’s progress before the crash below. Unfortunately, the audio track is missing, so it’s not always clear what the message is.
The conclusion?
You may wonder why someone didn’t pursue this project. We have no submarines, farms, mines, or hotels. Why not? It is true, of course, that the Navy continued to use limited saturation diving for specific, sometimes secret, purposes.
Well, the answer is complicated. The Navy’s work at Sealab directly created the technology and techniques used every day by local divers around the world, many of whom maintain underwater fuel production equipment. However, that is very special, and even then, a modern desert vehicle is a better choice for most tasks. Just as space is a difficult place to live, so is the ocean. Everything rusts and leaks.
Now, we are building space stations, and the day of the station at the bottom of the ocean will not come or will be in the future. But even so, the technology developed by these pioneers will inform human activities under the sea for the foreseeable future. Nowadays, robots are cheaper and more efficient in almost any task. However, there are times when only one will do it.
