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A Life Support Technician (LST) is an integral part of a bell diving team. Bell diving (also called mixed gas diving and saturation diving) is diving from a closed bell using mixed gas hot water suits and is generally performed in very deep water.

The responsibilities and actions of an LST directly effect and control the lives of the divers under their care. The primary responsibility of an LST is maintaining an environment to sustain life within the saturation diving complex.  This is quite a complex situation requiring high levels of expertise and care as the as the individual pressures of the various components of the gas mixtures can have very considerable physiological effects on the divers – the wrong mix can be lethal. The LSTs job includes appropriately maintaining oxygen levels, carbon dioxide levels, temperature & humidity. Constant monitoring of these, as well as the internal pressure (depth) must be undertaken to keep the divers safe and well.

There are three different categories of Life Support Technician including:

  • Assistant Life Support Technician (ALST) which is the entry level
  • Life Support Technician (LST)
  • Life Support Supervisor (LSS)

Tasks Performed on the Job

Life Support Technicians generally perform the following tasks:

  • Controlling of the running of the saturation control panel
  • Monitoring and calibration of oxygen and carbon dioxide analysers
  • Maintaining saturation watch, monitoring chamber environment and keeping it within appropriate parameters
  • Calibration of all environmental analysers
  • Logging all aspects of the chamber environment and its occupants
  • Maintaining saturation watch for 12 hour shifts and then being on emergency call out during the off-shift cycle
  • Mixing gas appropriately to suit saturation storage, diving and emergency breathing
  • Using high pressure compressors to move large quantities of gas to various storage cylinders
  • Operating gas reclaim and purification systems
  • Passing food and other necessary items into the chambers via the medical locks
  • Passing diving equipment into the chamber via equipment locks.

Assistant Life Support Technicians are generally in training to become LSTs and require at least 2400 logged panel hours before becoming an eligible candidate to sit the examination for the position of LST (see Career Pathways below). ALSTs are restricted to the following tasks:

  • Operating equipment such as medical/equip locks under direction and supervision of LST or LSS
  • Operating control panel valves under direct supervision by LST or LSS.

Life Support Supervisors have at least 2400 logged panel hours as an LST and have been able to demonstrate competence and suitability for the position through formal examination (see Career Pathways below). LSSs conduct the following tasks:

  • Gas mixing, purification, management and record keeping
  • Working out the appropriate gas mixes for various functions around the diving system such as the percentages for optimum partial pressures at a given depth for diving, emergency and therapeutic mixes
  • Producing the daily report that outlines each days usage of consumables such as gas, carbon dioxide absorbent & purafil odour absorbent
  • Liaising with the offshore installation manager, diving superintendent, diving supervisors and his subordinates (LST & ALST) as well as his opposite shift counterpart ast to the daily events.
  • Attendance at daily shipboard meetings prior to coming on shift.

Responsibilities and Challenges

Life Support Technicians

As mentioned above the primary responsibility of the LST to keep bell divers safe and well while working in a closed bell at depths down to 300m.

Responsibilities include:

  • Responsibilities extend to maintaining the Hyberbaric Rescue Craft and being part of it’s launch crew.
  • Keeping the diver’s nutritional balance is crucial and therefore meals are an important part of the LST’s responsibilities.
  • Hygiene is important due to the infection hazards of living in a warm, humid environment, so the lST must ensure laundry and linen are kept clean as does organizing and locking in equipment for chamber cleaning on a regular basis.
  • The diver’s equipment is required to be kept in a clean and ready state and to be locked into the divers  prior to the dive along with the bell scrubber canisters (CO2 absorbent), bellman’s lunch and water.
  • When divers become sick or injured it is the LST or LSS who liaises between the diver medics in the chamber and the ship’s medic or even the company medical consultant via satellite phone. In this way the appropriate treatment can be given to the sick or injured diver.
  • Communicating with divers, organising diver’s pre-bell run and then sending them to work.
  • Supervising the Transfer Under Pressure phase of bell turn around where returning divers come back from their 8 hour bell run and fresh divers are sent into the bell to complete their dive.
  • For keeping morale up within the saturation complex as the closed, cramped environment can lead to tensions among the chamber occupants. This can entail sending emails for the divers, organizing movies, music, charging batteries for PSP or MP3 players, routing phone calls to in-chamber phone systems.
  • He is responsible for the hyperbaric evacuation of the divers during an emergency both when on and off shift (role varies accordingly).
  • Help in the training of the ALST in the skills he will need to advance to LST.
Assistant Life Support Technicians

An ALST’s main responsibilities lay in having diver’s equipment ready for use when needed, organising and delivering meals & laundry.

Responsibilities include:

  • Housekeeping around the saturation system such as changing carbon dioxide absorbent in the chamber environmental control units and for the diving bell scrubbers.
  • Having the diving gear clean, dry and ready to go is critical to the operation and it falls to the ALST to have this in hand.
  • Ensuring laundry and linen for the divers is kept clean within the saturation complex because of the infection hazards of living in a warm humid environment.
Life Support Supervisors

An LSS has the same level of responsibility as diving supervisor. The LSS ultimately responsible for the hyperbaric evacuation of the divers within the saturation complex when on shift and they have off shift responsibilities for this evacuation as well. The LSS is must have managerial skills to control all the equipment, personnel and consumables used in saturation diving. The LSS is ultimately responsible for the divers within the saturation complex during a 12 hour shift as well the LST and ALST. The LSS also does the function of the LST and even the ALST. The LSS will also help train both the ALST and the LST in the skills they need for career advancement.


One of the challenges an LST/ ALST/ LSS faces on the job are to keep all the divers happy, healthy and safe during their time within the saturation complex. If mistakes are made lives can be lost, so thorough competence in, and understanding of, all the theory of saturation diving in combination with good clear communication skills (you may be working with divers of nationalities who have different accents and those accents are distorted by the effect of helium), good adherence to safe working practices and willingness to continually learn and improve your skills as an ALST/LST/LSS.
Long trips away from home in what are sometimes not the nicest of places, some saturation systems are older and are on older vessels. Often working in inhospitable climates e.g. very hot as in the middle east or freezing cold as in Sakhalin Island (Russia) or politically unstable areas such as West Africa. Other times the job can be on board more sophisticated vessels with more modern diving systems built into the ship itself. Work in Australian and New Zealand waters is usually of a higher safety standard and better working and living conditions than many other places.

What an LST/ALST/LSS Can Offer

Successfully meeting the challenges above and completing an incident free saturation where we all get to go home safely with the knowledge that a large pay packet will be forthcoming soon is one of the rewards of the job. In Australia an ALST earns in the vicinity of $1000/day,  LST approx. $1300/day and LSS approx. $1600/day. Industry is on a casual basis so there is no pay during time off. Overseas rates will differ.

How to Become an LST/ALST/LSS

A good starting place is to be a commercial diver so as to have a grounding in diving and its particular requirements and hazards. Diver Medic is also a good qualification to have. A nursing background (particularly hyperbaric and or intensive care nurse) is an ideal entrance to saturation life support.
Students have to attend an IMCA-certified course with a duration of 10 days (ADAS will soon offer an LST course also). This course is classroom based and covers topics such as diving physics and physiology, tables for saturation storage, excursions, saturation decompression, emergency and therapeutic decompression, legislation (optional), gas handling, gas mixing and analysis, gas reclaim, gas management, saturation diving systems and their equipment, operating and emergency procedures.

Career Pathways

A career path as an LST/ ALST/ LSS initially involves attending a recognized training course (currently IMCA and soon ADAS). After having successfully completed the course the new ALST has to find work and log 2400 hours of panel time. At the completion of the 2400 logged panel hours and demonstrated practical competence to his superiors, the ALST then gets a diving company (IMCA member) to put him forward as an LST candidate at which point he sits an exhaustive examination. If successful the qualification of LST is attained. Then having completed a further 2400 logged panel hours and once again demonstrated competence and suitability the LST may then be put forward by a diving company as an accredited LSS.

Thanks to Chris Laursen of  TeamsT  for contributing to this web page.

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