Saturation diving grew out of a simple idea formulated in the 1950s: once tissue is saturated with inert gas, keeping the diver under pressure no longer increases the required decompression time. From military experiments and the underwater habitats of the 1960s, it went, in barely a decade, to underpinning oil production in the North Sea.
Few industrial techniques have moved so fast from the lab to everyday work. In 1957 saturation was a physiological hypothesis; by the 1970s it was the only way to keep the North Sea's subsea infrastructure running. Understanding that journey explains a great deal about the trade as it is today, including some of its strictest rules.
The idea: once you're saturated, it doesn't matter how long you stay
The starting point is a physiological fact. When a person breathes gas under pressure, the tissues absorb inert gas until they reach equilibrium. Once that point, saturation, is reached, staying under pressure any longer adds no more dissolved gas, and so does not lengthen the decompression needed.
The practical consequence is huge: decompressing a diver costs the same after a day as after a month. If, instead of going up and down every shift, the diver is kept pressurised for weeks, the bottleneck that made prolonged deep work unworkable disappears. That is, in a sentence, the logic we explain in what a saturation diver is.
US Navy physician George F. Bond was the one who drove the systematic demonstration of that principle, in a programme of experiments known as Genesis, carried out in the late 1950s and early 1960s, first on animals and then on human volunteers in hyperbaric chambers.
The 1960s: habitats and records
The following decade was one of feverish exploration, along two parallel lines.
On one side, underwater habitats. Jacques-Yves Cousteau's team developed the Conshelf series from 1962 onward, with inhabited structures at increasing depths in the Mediterranean, the Red Sea and, in 1965, off Cap Ferrat, where a team of oceanauts lived and worked at around a hundred metres for weeks. The US Navy followed with SEALAB, with successive installations in 1964, 1965 and 1969.
Those programmes had a mixed aim, part scientific and part propaganda: to show that human beings could inhabit the seabed. They also showed the cost. SEALAB III ended in 1969 with the death of diver Berry Cannon during a job to repair a leak, and the programme was cancelled.
On the other side, depth records. In 1962, Swiss researcher Hannes Keller made an extraordinarily deep experimental dive off the Californian coast using mixtures of his own design. The dive reached its target depth, but ended in tragedy with the death of his companion, British journalist Peter Small.
The overall reading of those years is uncomfortable and honest: saturation was validated at a high human cost, and much of the procedure-driven culture of today's industry has its roots there.
The 1970s: oil changes everything
What turned saturation into an industry was not the science, but the oil. Developing fields in the North Sea required installing and maintaining structures at depths and in conditions where conventional diving could not keep up, and it required it fast.
Demand triggered a wave of shipborne saturation systems, first on platforms and barges and later on purpose-built vessels. The companies that still form the backbone of the sector today appeared, and the first generation of professional saturation divers took shape, often learning on the job.
It was a time of rapid growth and a high accident rate. The North Sea of those years is where the trade's reputation, for better and for worse, was forged, and it remains its capital, as we describe in this article. At the same time, in France, the company Comex ran an extreme-depth research programme that carried out experimental dives well below normal working depths, both at sea and in chamber.
The accidents that wrote the rules
Two events marked the shift toward today's safety culture.
The first was the explosive decompression that occurred in 1983 in the saturation system of the Byford Dolphin platform, in Norwegian waters, when a hatch was wrongly opened while the system was pressurised, causing the instant death of four divers and a chamber attendant. The case transformed transfer procedures and the mechanical interlocks fitted to systems.
The second, although it was not a diving accident, was the 1988 Piper Alpha platform fire, which completely reorganised British offshore safety regulation and, with it, the framework divers work under. We cover it in detail in what happened at Piper Alpha.
That period also produced the consolidation of the sector's codes of practice and the role of the international marine contractors' association that we describe in what IMCA is.
From the 1980s to today: robots, standards and maturity
From the 1980s onward, the arrival of remotely operated vehicles changed how tasks were split up. Extreme depths and observation work went to the machine, and human diving concentrated on the depth range and the tasks where manual intervention is still more effective. We look at that balance, which is still shifting, in ROV vs diver.
At the same time, the profession became ordered: recognised certification schemes, an annual medical requirement, standardised limits on campaign length, redundant systems and hyperbaric rescue capsules. The result is a trade that is still demanding but bears little resemblance to that of the 1970s. Today's pathways are set out in certifications and in how to become a commercial diver.
The geographical map also widened: from the North Sea to Brazil, West Africa, the Persian Gulf, Southeast Asia and Australia, a picture we cover in where saturation diving work is found.
What remains of all that
What remains is the technique, its principle practically unchanged: compress, live under pressure, work in shifts from a bell and decompress just once at the end. And what remains is a professional culture built on costly mistakes, which explains why in this trade procedures are followed to the letter and why nobody improvises.
For anyone entering the sector today, that history is not folklore. It is the reason the rules they'll find actually exist.
Extreme depths and the ceiling of human diving
Between the 1970s and 1990s, research programmes were run to find out how far a human being could go working under pressure. Experimental dives were carried out in chamber, and some operational ones at sea, at depths well beyond those of normal commercial work, using special mixtures and extremely slow compressions to mitigate high pressure nervous syndrome.
Those programmes established something important: there is a practical ceiling. Beyond a certain depth, the physiological effects of pressure, gas density and the time needed to compress and decompress mean that human intervention stops being reasonable against the robotic alternative.
That is why commercial saturation work is concentrated in a given depth range, and what lies below it belongs to machines. It is not an unresolved technological limitation, but a fairly stable physiological boundary.
What the history teaches anyone starting out today
There's a useful lesson here for the aspiring diver. The first generation learned on the job and paid for it; today's generation inherits a body of knowledge that lets it do dangerous work with controlled risk, as long as the method is respected.
Hence the sector's insistence on recognised certification, rigorous logging of dives and traceability of everything that's done. It isn't bureaucracy: it's how a small industry keeps hold of what it has learned.
And there's a second lesson, a less technical one: saturation exists because it turned out to be profitable, and its volume of work has always followed investment in subsea infrastructure. Understanding that dependence helps read the market realistically, something we apply in how many saturation divers there are in the world.
Frequently asked questions
Who invented saturation diving?
The systematic formulation of the principle and its experimental demonstration are credited to US Navy physician George F. Bond, who drove the Genesis programme in the late 1950s and early 1960s, first with animals and then with human volunteers in chamber.
What were the SEALAB and Conshelf programmes?
They were experimental underwater habitats from the 1960s. Conshelf, run by Jacques-Yves Cousteau's team, and SEALAB, run by the US Navy, aimed to show that it was possible to live and work for extended periods under pressure on the seabed.
When did the industry start using saturation?
In the 1970s, driven by the development of North Sea oil fields. The need to install and maintain subsea structures at significant depths turned an experimental technique into an industrial service in a very short time.
What happened in the Byford Dolphin accident?
In 1983, in that platform's saturation system in Norwegian waters, a hatch was wrongly opened while the system was pressurised, causing an explosive decompression that killed four divers and a chamber attendant. The case changed transfer procedures.
Why does the history of saturation diving matter today?
Because today's rules largely come from specific accidents. Hatch interlocks, campaign limits, medical requirements and transfer procedures all respond to documented failures from the past.
Have the techniques changed much since then?
The principle hasn't changed: compress, live under pressure, work from a bell and decompress just once at the end. What has changed is the environment: safer, redundant systems, certification standards, medical oversight and the split of tasks with remotely operated vehicles.
Published 22 August 2026 · By Arthur More, professional saturation diver
Photo: infomatique · CC BY-SA via Openverse
This article is part of our in-depth guide to what a saturation diver actually earns — the complete picture, with sources.
This article is part of our in-depth guide to what a saturation diver actually earns — the complete picture, with sources.
This article is part of our in-depth guide to what a saturation diver actually earns — the complete picture, with sources.
This article is part of our in-depth guide to what a saturation diver actually earns — the complete picture, with sources.