The Life Support Technician is the technician who keeps the saturation system habitable: controlling gas mix, pressure, temperature, humidity and CO2 removal in the chambers where the divers live. They work continuous shifts at the control panel and answer to the saturation supervisor.
In a saturation system there are two groups of people who depend on each other completely. Inside the chambers are the divers, living under pressure for weeks. Outside, at the life-support control panel, is the team keeping that atmosphere within tight limits around the clock. That team is made up of the Life Support Technicians, abreviado LST.
It's one of the least known roles in the industry, and yet one of the most critical. It's also one of the few serious career paths within saturation diving that doesn't require getting in the water. For a lot of people who want to work offshore but don't meet the medical requirements to dive, or who want to stay in the sector after they stop diving, the LST role is the way in.
What a Life Support Technician actually is
The LST is the technician responsible for maintaining and monitoring the atmosphere of the saturation system while personnel are pressurised inside. The system isn't just the bell: it includes the living chambers, the transfer chambers, the gas supply system, climate control, sanitation and the material locks. All of that is an artificial environment that stays habitable only because someone is actively managing it.
The work is done from a console with analysers, gauges, flow controls, video monitors and comms with the chambers. The LST talks to the divers throughout the day, passes food and material through the locks, logs parameters in the log and signs off every shift change. On a system with divers inside, the panel is never left uncovered.
What they actually control
The gas mix
The divers breathe heliox: a mixture of helium and oxygen. The key figure isn't the oxygen percentage but its partial pressure. At storage depth, an oxygen fraction that would be insufficient at the surface is perfectly breathable, and a normal fraction would be toxic. The LST monitors that partial pressure continuously and corrects it by injecting oxygen as the occupants consume it.
Carbon dioxide
The divers exhale CO2 constantly, and in an enclosed volume it builds up. The system circulates the atmosphere through scrubbers with soda lime that absorb it. The LST monitors the CO2 reading, schedules cartridge changes and checks that the circulation fans are working. A fault here shows no obvious symptoms until there's already a problem, which is why redundant monitoring is insisted on.
Temperature and humidity
Helium conducts heat much better than nitrogen. That means a heliox atmosphere at thirty degrees can feel cold, and the comfortable thermal margin is narrow: a few degrees separate discomfort from the risk of hypothermia. The LST adjusts chamber heating and watches humidity, which if it rises encourages skin and ear infections, a classic problem on long projects.
Pressure and profiles
Compressing and decompressing isn't a matter of opening a valve. Compression is done at an agreed rate to avoid high pressure nervous syndrome, and the final decompression follows the contractor's table, which can take several days at a rate of tens of metres per day. The LST runs that profile under the supervisor's direction and documents any deviation.
Hygiene, food and waste
Part of the job is pure logistics: passing food trays through the lock, removing waste, handling laundry, sending in tools or medication. It sounds minor, but it's what makes twenty-eight days locked in sustainable, and a badly operated lock is a route to depressurisation.
How people get into the role
There's no single way in. The three usual routes are these:
From diving. Many LSTs are former saturation divers. They already know the system from the inside, understand what it feels like on the other side of the glass, and have seen how an emergency is handled. It's a natural move when the medical fitness gets complicated, or when someone wants to cut down on physical wear without leaving the sector.
From deck. The classic route is to start as a life support supervisor's assistant or system technician, helping with maintenance, cylinder changes, cleaning and rig-up, and clocking up hours at the panel until you're trusted with a shift. It takes patience: you don't learn it on a course, you learn it in hours on the system.
From a technical specialty. People with a background in clinical hyperbarics, the navy, industrial refrigeration or instrumentation fit in well because the analysers, valves and climate control side of it feels familiar to them.
In all three cases you need the offshore safety training required by the region you'll work in and a valid medical. If you're starting from zero, the general route is described in how to train for commercial diving.
IMCA certification
The International Marine Contractors Association runs a certification scheme for life support personnel, with separate levels for technician and for life support supervisor. The scheme is built on a combination of training, documented hours of system experience and endorsement from the employing company. It isn't an academic qualification you get on your own: it's built up with a verifiable work record.
This has an important practical consequence. An LST's employability depends as much on the certificate as on the track record of systems they've worked on, because every manufacturer and every vessel has its own quirks. You can get more context on which bodies matter in certificaciones in commercial diving and in the article on what IMCA is and why it carries so much weight.
What the day-to-day work is like
The usual pattern is twelve-hour shifts, with offshore rotations that typically run several weeks on board followed by an equivalent period on shore. Unlike the diver, the LST isn't pressurised: they sleep in their cabin and leave the vessel at the end of the rotation as normal.
The mental load is different from diving. Much of the shift is watched routine: reading, logging, adjusting, checking. And that's exactly why the professional risk of the role is complacency. Procedures are written so the routine doesn't turn into autopilot, and the handover handover between shifts is a formal ritual, not a chat.
The other half of the job is the relationship with the divers. You spend weeks talking over the intercom to people who can't leave. A good LST knows how to read the tone, spot when someone isn't right, and flag it to the supervisor before it becomes a problem.
Why it's a solid career path
There are several reasons this role is worth having on your radar:
First, demand is tied to active saturation systems, not to the number of divers. Every system in operation needs continuous life-support coverage, so the minimum crew per vessel is stable.
Second, it doesn't depend on your ability to decompress. There are medical requirements — it's offshore work — but they're noticeably less demanding than a saturation diver's.
Third, it's a career with room to grow. From technician you progress to life-support supervisor, and from there to system responsibility, training or technical roles with the contractor. The parallel progression on the diving side is explained in how you become a diving supervisor.
Fourth, the skill set is transferable within the sector. Knowledge of hyperbaric systems opens doors with equipment manufacturers, treatment chambers and research projects, not only in contratistas offshore.
A typical shift at the panel
To make it clearer, here's what a normal handover looks like. You arrive fifteen or twenty minutes early. The outgoing colleague briefs you on the state of play: storage depth of each chamber, latest oxygen and CO2 readings, temperature, which divers are inside and at what stage, whether there's a bell in the water, which scrubbers have been changed and when, what open issues there are, and what's planned for the next twelve hours.
Then you sign on. From that point, whatever happens on that system is yours. The rest of the shift is a repeating cycle: reading rounds at fixed intervals, logging, fine oxygen adjustments, climate control, meal service through the lock, and periodic comms with the chambers. In between, scheduled maintenance, alarm checks and preparing for whatever the next shift brings.
When there's a bell in the water, the pace changes. The LST keeps track of gas consumption, the bell's own atmosphere, and coordination with the diving supervisor. If something goes wrong — a loss of supply, a diver coming back early, a reading that doesn't add up — the life-support panel is one of the central pieces of the response.
What it pays and what career it offers
The exact figures depend on the contractor, the region and whether the contract is by day or by rotation, and they vary enough that giving a number here would be misleading. What can be said in relative terms is that an LST earns more than most deck technical roles and less than a saturation diver on a project, which is the sector's salary peak because of the saturation premium. The general pay context is in how much a diver earns.
In exchange, the career is longer and more stable. A saturation diver has a professional window limited by physiology and by medical checks; a life support technician can stay in the role for many more years and move into life-support supervision, system responsibility, training or technical roles with manufacturers and contractors. Sector job listings and agencies are gathered in jobs and agencies.
What's expected of you
If I had to sum up the profile in four traits: discipline with paperwork, tolerance for routine without letting your guard down, the ability to communicate clearly under stress, and absolute honesty about mistakes. In life support, hiding an odd reading or an unlogged adjustment is infinitely worse than having made the mistake in the first place. The whole safety system relies on the log data being true.
Frequently asked questions
What exactly does a Life Support Technician do?
They keep the saturation system's atmosphere habitable while pressurised divers are inside: controlling the partial pressure of oxygen, removing carbon dioxide, and managing the temperature, humidity and pressure of the chambers. They also manage passing food and material through the locks, log all parameters, and run the compression and decompression profiles under the supervisor's direction.
Do you have to be a diver to work as an LST?
It isn't essential. Many LSTs are former saturation divers, but people also come in from deck as a life-support assistant, or from technical specialties such as clinical hyperbarics, instrumentation or industrial refrigeration. You do need the offshore safety training required by the region and a valid medical for work at sea.
What certification does a Life Support Technician need?
IMCA runs a certification scheme for life support personnel, with separate levels for technician and for supervisor. It's based on training, documented hours of experience on real systems and endorsement from the employing company, so it isn't obtained independently on a short course: it's built up with a verifiable work record over time.
Is the LST pressurised with the divers?
No. The LST works at the surface, at the life-support control panel, and sleeps in their cabin like the rest of the vessel's crew. Only diving personnel enter the chambers. That means the LST can leave the vessel at the end of their rotation without having to go through a decompression process.
What are an offshore LST's shifts like?
The usual pattern is twelve-hour shifts with continuous panel coverage for as long as personnel are pressurised, within offshore rotations of several weeks on board followed by an equivalent period ashore. The handover between shifts is done with a formal, documented handover, not an informal chat, because data continuity is part of the safety system.
Published 21 August 2026 · By Arthur More, professional saturation diver
Photo: PiktourUK · CC BY via Openverse
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.