Death-Defying Jobs: Saturation Diving

A diver welding underwater at a depth of 65 feet.
A diver does underwater welding at 65 feet below the surface. Photo Courtesy: Alexis Rosenfeld/Getty Images

Have you ever looked at an offshore oil rig or thought about a pipeline on the ocean floor and wondered: Who fixes that thing when it breaks? Well, that person doing tough jobs deep underwater is often a saturation diver!

If you’ve never heard of saturation diving, prepare yourself for a mind-blowing look at one of the most extreme and death-defying jobs out there. A career in saturation diving comes with a brutal set of physical and mental demands, but it can be quite an adventure for the right type of person.

What Is Saturation Diving?

Saturation diver works on a hydraulic ram at the wreck of the USS Monitor, 230 feet below the ocean’s surface. Photo Courtesy: U.S. Navy photo by Chief Photographer’s Mate Eric J. Tilford/Wikimedia Commons

To explain what saturation diving is, first we need to talk about what pressure does to the human body.

If you’ve ever gone scuba diving, you know that it involves breathing compressed air from a tank. The deeper underwater you go, the greater the pressure on your body. All this pressure causes nitrogen and other inert gasses in the air you’re breathing to start dissolving into your blood and body tissues. The longer you stay deep underwater, the more these gasses saturate (fill) your tissues and blood. And that’s perfectly safe — as long as you don’t return to the surface too quickly.

If you’re deep underwater for long enough to become saturated, you’ll need to undergo a process called decompression before you surface. You rise very slowly to shallower depths, pausing at regular stops along the way. This lets the gasses filter slowly and safely out of your blood and tissues. If you come up too fast, you risk getting decompression sickness (more on that later).

And the deeper down you go, the slower you need to come up. For example, if you dive to 650 feet and stay there long enough to become saturated, you need eight whole days to decompress!

Saturation diving was invented as an alternative to having divers do these long decompressions after every shift of underwater work. Rather than pressurizing and depressurizing over and over, saturation divers live in a small, pressurized chamber for weeks or even months at a time. The chamber is housed in a support vessel on the surface — usually a large ship. But the pressure inside the chamber is the same as the pressure on the ocean floor where the divers do their work.

What Do Saturation Divers Do?

Saturation diver working on the USS Monitor wreck at 230 feet below sea level. Photo Courtesy: U.S. Navy Photo by Photographer’s Mate 2nd Class Petty Officer Eric Lippmann/Wikimedia Commons

So, what do these divers do while living under pressure for all that time? When they’re not in their pressurized living chamber, saturation divers travel each day to the sea floor in a diving bell to put in a shift at work.

Many of them work in the oil and gas industry. They spend their underwater days inspecting, repairing or maintaining offshore oil wells, pipelines or rigs. Sometimes the jobs involve deconstructing large underwater structures that are no longer in use. 

We know what you’re thinking: Why not just send robots? When saturation divers are called in, it’s to do a job that a machine just doesn’t have the maneuverability to do — or where human judgment is an important part of getting the job done correctly and safely. Some saturation dives are on par with heavy construction jobs, but with the added complication of working hundreds of feet below sea level. 

While submerged, divers are dependent on a team of top-side specialists to keep them alive. Their food gets sent into the living chamber through airlocks — and of course they need a constant supply of air to breathe. (Although at the pressures they reach, they actually breathe a mix of helium and oxygen called heliox.)

Dangers of Saturation Diving

A diver works at 190 feet below sea level. Photo Courtesy: Mahmut Serdar Alakus/Anadolu Agency via Getty Images

What could possibly go wrong when working with heavy equipment while submerged hundreds of feet underwater? So much!

One of the most well-known dangers of deep-sea diving is decompression sickness, also called the bends. This happens when divers return to surface pressure too quickly. A sudden pressure change makes the gasses in the the diver’s body expand and form bubbles. The bends are very painful and can cause serious problems like nerve damage and paralysis. Severe cases can cause death.

Breathing helium comes with complications as well. It makes divers shed more body heat and can lead to hypothermia, so the chambers are kept very warm and divers need heat pumped into their diving suits along with the heliox they breathe. (Also, while this doesn’t exactly count as a health risk, it’s amusing to note that heliox has the same vocal effect as helium from a balloon. So your voice sounds like a high-pitched cartoon character the entire time.)

When actually out in the ocean working, divers are constantly at risk of getting their heating or breathing tubes disconnected. They’re also in danger of being crushed by heavy objects that have come loose from underwater construction sites.

And one of the gnarliest risks of all can happen when something goes wrong with the pressurized seal on either the pressurized living chamber or the diving bell. For example, if there’s an equipment failure and this seal gets broken, the divers can experience what’s called explosive decompression. This means that their bodies go from very high pressure to very low pressure in an instant. We won’t go into all the unpleasant details here, but it’s safe to say that this is a deadly outcome.

Risk vs. Reward

Two professional divers carry a section of pipe on the ocean floor. Photo Courtesy: Alexis Rosenfeld/Getty Images

As you may have already gleaned, being a saturation diver involves plenty of risks. These divers’ lives depend on many factors remaining in perfect balance throughout the entirety of the dive. Luckily, their pay rate takes all this into account. 

According to the Divers Institute of Technology, saturation divers can make around $1,400 per day and anywhere from $30,000 to $45,000 per month. If they work regularly, that can easily work out to a salary of over $150,000 per year. Depending on the dive, they may earn even more based on things like the depth of the dive and the length of time spent underwater. 

The trade-off, of course, comes with the physical and mental demands of the job. Not only can saturation diving take a toll on your physical health, but living in a tiny metal chamber with four or five other people for weeks at a time comes with its own unique set of mental demands.

Still Not Scared? Here’s How You Become a Saturation Diver

A diving student sits in a decompression chamber. Photo Courtesy: Alexis Rosenfeld/Getty Images

Saturation diving is definitely not for the faint of heart — and it probably won’t be a great career choice if you’re claustrophobic. But if you think you can spend weeks living under extreme pressure, then here’s what you need to know.

The first thing you’ll need to do is get certified as a professional commercial diver. Diving schools usually only require a high school diploma or GED for entry into these courses. Before you move on to more specialized training, you’ll need several years of experience with regular commercial diving. You’ll also need to get experience with mixed-gas diving (where you’re breathing the heliox mixture or a similar mixture).

Then you’ll need to complete a specialized saturation diving training program. Due to the intense demands of the job, only the most experienced and skilled divers get into these programs. And only a small number of schools offer these programs, so you’ll have to do some research to find a spot.

We hope you’ve enjoyed this look into the wild and crazy world of saturation diving!