Connect with us

Diving Safety

What Happened to Solid State Oxygen Sensors?

The news in 2016 that Poseidon Diving Systems would be incorporating a solid state oxygen sensor in their rebreathers sent a buzz through the rebreather community. Galvanic sensors, along with their legacy-1960s “voting logic” algorithms to boost reliability, had long been considered the weakest link in closed circuit rebreathers. Many heralded Poseidon’s subsequent 2017 roll-out as the dawn of a new era in rebreather safety. Five years later, Poseidon remains one of two companies (the other strictly military) to have adopted optical sensors. Technology reporter and tech diver Ashley Stewart examines some of the reasons why.

Published

on

by Ashley Stewart.

Header image: Karst Underwater Research (KUR) rebreather divers at Weeki Wachee. Photo by Kirill Egorov

For years, it’s been said there’s a revolution coming for the closed-circuit rebreather— a new, more reliable, safer replacement for the traditional electro-galvanic oxygen sensor, widely considered the weakest component of rebreathers. In March 2017, that revolution looked to be just over the horizon. Poseidon Diving Systems began shipping an offboard solid state sensor to supplement the MKVI’s and SE7EN’s galvanic sensors and offered to license the technology to other manufacturers. Though Poseidon subsequently incorporated the solid state sensor into its SE7EN rebreathers, nearly five years have passed, and not much else has changed.

Poseidon remains the only manufacturer using solid state sensors in recreational rebreathers. No other companies have licensed Poseidon’s technology. Major tech diving manufacturers—including JJ-CCR and Divesoft—say they don’t believe the technology in general is ready for use in rebreathers. Some manufacturers worry that the sensors won’t function accurately in humid environments over a wide range of pressures, and they claim that addressing these challenges will be costly. Meanwhile, divers who tested Poseidon’s sensors offered mixed reviews, and even the inventor who sold the sensor validation technology patent to Poseidon believes they should be used along with traditional sensors. (Poseidon gives divers the option of combining the sensors).



Poseidon’s solid state sensor integrated into the SE7EN rebreather. Photo courtesy of Poseidon.

Oxygen sensors are the enabling technology that made mixed gas rebreathers possible, replacing rebreathers that could only be used with pure oxygen. In 1968, marine scientist Walter Starck introduced the first commercial CCR, called the Electrolung, which used polarographic sensors. The next year, BioMarine Industries launched its CCR-1000, the predecessor of the US Navy’s Mk-15/16. The unit was the first mixed gas rebreather to use galvanic sensors, which do not require a power supply. 

In addition to removing a diver’s exhaled carbon dioxide, a rebreather must measure and maintain a safe and efficient level of oxygen, as measured by the partial pressure of oxygen, or PO2, via oxygen sensors.

Measuring PO2 correctly is critical, and failures can be fatal. Too little oxygen can cause hypoxia and loss of consciousness, and too much can result in central nervous system toxicity and convulsions. Since sport divers began using CCRs over twenty years ago, both conditions have caused numerous drowning fatalities.

With the exception of Poseidon and military manufacturer Avon Underwater Systems, modern close circuit rebreathers have more or less used the same type of sensor since the 1960s. Rebreathers typically use three galvanic sensors, averaging the readings of the two closest sensors and ignoring the third in a protocol called “voting logic,” originally created by Starck in response to the sensors’ noted unreliability.

Even with this voting logic, however, the sensors can be unreliable (See “PO2 Sensor Redundancy” in Dive Deeper below). The galvanic sensors are cheap and time-tested, but they need to be recalibrated before every dive and expire after about a year. The new sensors—called “solid state sensors” or optical sensors—are expected to be more precise, reliable, and durable, though significantly more costly.

An illustration of luminescent quenching technology

Galvanic sensors are essentially wet-cell batteries that generate a millivolt current proportional to the PO2 in the loop. Conversely, Poseidon’s solid state sensor uses luminescent quenching, wherein a red LED light excites the underside of a special polymer surface, which is covered with a hydrophobic membrane and exposed to the gas in the breathing loop. A digital color meter then measures the responding change in fluorescence, which is dependent on oxygen pressure, and an algorithm calculates the PO2.

Experts more or less agree that the right solid state sensor could make rebreathers safer, but the market is split on whether the technology is ready for use in rebreathers and just how much better they’d have to be to justify the cost.

Field Test Results

Poseidon advertises its sensor as “factory-calibrated and absolute, delivering unsurpassed operating life, shelf life, and calibration stability.” Richard Pyle, a senior curator of ichthyology at Hawaii’s Bishop Museum who works with Poseidon-affiliated Stone Aerospace, has tested Poseidon’s sensors for years, initially as a passive offboard check against Poseidon’s traditional galvanic sensors. Later, in November 2019, he said he began testing Poseidon’s prototype with the solid state sensor as the primary sensor in the unit. “From my perspective as a rebreather diver, this is the most significant game-changing way to know what you are breathing,” Pyle said. “We will never go back to the old oxygen sensors.”

Poseidon divers at 110 m/359 ft. Photo by John L. Earle

Pyle said he’s yet to fully analyze the data he’s collected to compare the performance of the solid state sensors against the galvanic sensors, but that  he’s had zero failures with the solid state sensors in the time he would have expected to have 50 to 100 failures with the galvanic sensors.

Likewise, Brian Greene, a Bishop Museum researcher who has tested the Poseidon sensors with Pyle, estimated that he’s made hundreds of dives with the solid state sensors without failure. But, not everyone has had this experience.

Sonia Rowley, an assistant researcher at the Department of Earth Sciences in University of Hawai’i at Mānoa, told InDepth that she experienced a variety of repeated failures when testing Poseidon’s system alongside Pyle beginning in 2016 and 2017, and Rowley dictated to InDepth specific dive logs detailing many of the failures. She wrote about her experience in the book “Close Calls.

Poseidon CEO Jonas Brandt said the company has tested the sensors since 2017 at different depths and temperatures, and that it has only seen one possible failure.


  • Fourth Element
  • Halcyon Sidemount
  • DIVE RITE

Arne Sieber is a sensor technology researcher who said he developed the O2 sensor validation technology used in the Poseidon rebreather and sold the patent to Poseidon. Sieber is now researching uses for the solid state sensor including in the medical market. He told InDepth he believes the best way to incorporate the solid state sensors into rebreathers would not be to substitute one for the other, but to combine sensor types and design a rebreather that incorporates both. 

Traditional galvanic sensors have advantages over the solid state sensors, Sieber said—they’re cheap, simply designed, low-voltage, and time-tested. Also, while solid state sensors are very accurate at measuring low PO2, they become less sensitive at about 1.6 bar, and are more prone to incorrect readings of higher PO2 levels than galvanic sensors. As for whether the sensors can function in humid environments, Sieber said the sensors can work well in liquids, such as when used for blood analysis (though the sensors are used to measure much lower partial pressures of oxygen) and for measuring oxygen content in the sea. Liquid can delay the amount of time it takes a sensor to read a partial pressure, but it does not falsify the results, Sieber said. Of Poseidon’s system, Sieber said, “It’s a good start. It’s very important that someone starts. Someone always has to be the first one.”

Brandt said divers have the option of combining sensors in the company’s SE7EN rebreather, using either two galvanic sensors, two solid state sensors, or one of each, and said it could be argued that using one of each sensor is the most reliable.

Meanwhile, a catalyst may be coming to encourage the development and adoption of solid state sensors in Europe, Sieber said. European Union rules restrict the use of hazardous substances in electrical and electronic equipment, but galvanic sensors (which have an anode made of lead) have been granted an exemption in medical products because there is not a suitable alternative. The exemption is set to expire.

Poseidon’s solid state sensor sells to end users for as much as around $1,500USD, and its SE7EN rebreather units use a maximum of two onboard sensors. [Note: Poseidon sells the sensor for 6800SEK plus VAT from its website, which equates to 944 USD, some outlets in the states sell them for much higher]. Galvanic sensors, meanwhile, cost around $100USD, last one year and divers use three at a time. And, that’s just the cost of the sensors themselves: Manufacturers have to make significant investments in, and upgrades to, electronics systems to accommodate solid state sensors. 

Fathom rebreather lid showing its galvanic sensors. Photo courtesy of Fathom Dive Systems, LLC.

As for how long the sensors actually last, even the manufacturers don’t yet know. Poseidon has some from 2014, and they still work but have to be factory calibrated every two years. Galvanic sensors need to be replaced annually, while solid state sensors are expected to last much longer.

Brandt chalks the debate about its sensors up to competitiveness in the market. “I don’t think anyone likes that somebody cracked the nut,” Brandt told InDepth. Poseidon is ready to share the technology with other dive companies and manufacturers, Brandt said, but there have been no deals to date. “We wanted to raise the bar in technology and safety with the rebreathers, and to be honest, we haven’t said to anyone in this business that this technology is exclusive or proprietary.”

Market Interest

When the company first debuted its sensor, Brandt reported that companies like Hollis and Shearwater Research expressed interest in licensing the technology, but nothing has come so far of those discussions. Brandt did say one manufacturer reached out right before the pandemic. He declined to say which, but shared that it was a European company. Hollis brand manager Nick Hollis said his team recalls a conversation with Poseidon, but that it was back in 2014 or even earlier.

Shearwater director of sales and marketing Gabriel Pineda said the company is still interested in solid state sensors, but they see an issue with the price. “If you make the economic case of traditional galvanic sensors versus solid state or optical sensors, you have to dive a lot, and it takes a long time for these to make economic sense for a diver.”

Of course, Shearwater is not a CCR manufacturer, but the company is interested in seeing whether the sensors would be viable for use with its electronic control system that is used by a majority of rebreathers on the market. Shearwater currently has no immediate plans to license the technology from any manufacturer but Pineda said the interest remains. 

Meanwhile, Poseidon’s solid state sensor CCR is still making headway, Brandt said. The current biggest buyer of the Poseidon units is the military (Brandt said three European Union countries’ forces are actively using the sensors). The sales have continued throughout the pandemic, and, over the past six months, Poseidon has started an upgrading program, allowing divers to add the new sensors to their old units. Poseidon is looking into a program Brandt compares to Apple Care, where customers can pay a fee for maintenance throughout the life of the sensor.

Solid state sensors replace numerous galvanic sensors which have a one-year life. Photo courtesy of Richard Pyle.

Meanwhile, Avon Underwater Systems is using three solid state sensors in its MCM100 military rebreather. Kevin Gurr, a rebreather designer and engineer who sold his company, VR Technology Ltd., to Avon, said the company uses the sensors “because of the increased safety and the decreased user burden as far as daily calibration.”

Gurr, who designed and produced the Ouroboris and Sentinel closed circuit rebreathers at his prior company VR Technologies Ltd., believes it’s the cost that has discouraged other manufacturers. “It shouldn’t be about cost at the end of the day,” Gurr said. “The digital interface is so much safer.”

Martin Parker, managing director of rebreather manufacturer AP Diving, said his company follows solid state sensor development but has yet to come across a sensor that meets its accuracy requirements. One such sensor using luminescence quenching can achieve good accuracy through a replacement disk the user must apply to the sensor surface after each use.

“Having been in the diving business for 50 years, we don’t believe it is on any diver’s wish list to have to re-apply every diving day a new component, as simple as that is to do,” Parker told InDepth. “With no easy external measure of accuracy prior to the dive, it is easy to foresee that many divers would ‘push their luck’ and use the discs for multiple days, then when they get away with it, they would encourage other divers to do the same… with the inherent risk of DCS or O2 toxicity.”

Parker said that he’s aware of two additional sensors under development, but neither has shown a working product yet. He declined to identify any of the manufacturers, citing commercial sensitivity. “Hopefully, we will get these to evaluate in the next 12 months,” Parker said.

Divesoft co-founder Aleš Procháska said he believes Poseidon’s approach to the sensor could “lead to success.” Speaking generally about solid state sensors rather than about Poseidon’s specifically, Procháska said his company isn’t yet utilizing solid state sensors because he believes the sensors are unable to function in humid environments with extreme water condensation and not applicable over a  wide range of pressures. To be able to use one of these sensors in a rebreather, Divesoft wants it to be durable in high humidity, consume less energy, and have a good price-to-lifetime ratio. 

“It is possible to build a CCR with the currently available O2 solid state sensor but not without sacrificing important properties of the breathing apparatus,” he said, such as size and energy. “Overall, the reasons why no one currently sells this technology on the market seems to be quite simple. It’s extremely difficult to come up with a suitable and functional principle that would lead to a cheap, small, and low energy consuming solid-state sensor. Despite this, I do believe that it’s only a matter of time until someone solves this one.” Asked via email about the status of DiveSoft’s own work on the technology, Procháska replied, “Well, as I said earlier, it’s just a matter of time,” adding the text, “Aleš smiles.”

JJ-CCR lid showing its three galvanic sensors. Photo by Kees Beemster Leverenz.

Halcyon COO Mark Messersmith said that divers are slow to embrace new technologies in general, and the current sensors just aren’t deficient enough to merit widespread adoption or the investment from manufacturers. “It’s not unlike many other technologies,” Messersmith told InDepth. “People are often slow to embrace a new technology if the existing technology is functional. The existing tech needs to be vastly deficient, and existing oxygen sensors are still largely functional.” 

The bottom line: Solid state sensors might very well be safer, but there isn’t enough incentive for the market to make them a reality. 

David Thompson, designer of the JJ-CCR, told InDepth they don’t use the sensors because he doesn’t believe the technology is ready yet and research in that area is extremely expensive and difficult for what he believes is essentially a small market. “Analog cells have a long history, and in the right hands are very reliable, easily available, and have a long history of working in a rebreather environment which is very hostile,” Thompson said, adding that high humidity and temperature in a rebreather is a challenge for any sensor. “I am sure it will be in the future, but that future won’t be here yet.”

Dive Deeper:

InDepth: Where Have All the Sensors Gone? Assessing the Global Oxygen Sensor Shortage

Rebreather Forum 3 Proceedings: PO2 Sensor Redundancy by Nigel A. Jones p. 193-202

Alert Diver: Oxygen Sensing in Rebreather Diving by Michael Menduno

Wikipedia: Electro-galvanic oxygen sensor


Photo by Daniel McMath 

Ashley Stewart is a Seattle-based technology journalist and GUE Tech 1 diver. Reach her via email: ashannstew@gmail.com, Twitter: @ashannstew, or send a secure message via Signal: +1-425-344-8242.

Diving Safety

Does The Sport Diving Community Learn from Accidents?

Do we learn from accidents as a diving culture and, as a result, take the actions, where needed, to improve divers’ safety? Though we might like to think that’s the case, the reality is more complicated as human factors coach Gareth Lock explains in some detail. Lock offers a broad six-point plan to help the community boost its learning chops. We gave him an A for effort. See what you think.

Published

on

By

by Gareth Lock

Learning is the ability to observe and reflect on previous actions and behaviours, and then modify or change future behaviours or actions to either get a different result or to reinforce the current behaviours. It can be single-loop, whereby we only focus on the immediate actions and change those, e.g., provide metrics for buoyancy control during a training course, or double-loop where the underlying assumptions are questioned, e.g., are we teaching instructors how to teach buoyancy and trim correctly? The latter has a great impact but takes more time, and more importantly, requires a different perspective. Culture is the ‘way things are done around here’ and is made up of many different elements as shown in this image from Rob Long. Learning culture is a subset of a wider safety culture.

Regarding a safety culture, in 2022 I wrote a piece for InDEPTH, Can We Create A Safety Culture In Diving? Probably Not, Here’s Why,” about whether the diving industry could have a mature safety culture and concluded that it probably couldn’t happen for several reasons:

  • First, ‘safe’ means different things to different people, especially when we are operating in an inherently hazardous environment. Recreational, technical, cave, CCR and wreck diving all have different types and severities of hazards, and there are varying levels of perception and acceptance of risk. The ultimate realisation of risk, death, was only acknowledged in the last couple of years by a major training agency in their training materials. Yet it is something that can happen on ANY dive.
  • Second, given the loose training standards, multiple agencies, and instructors teaching for multiple agencies, there is a diffuse organisational influence across the industry which means it is hard to change the compliance-focus that is in place. From the outside looking in, there needs to be more evidence of leadership surrounding operational safety, as opposed to compliance-based safety e.g., ensuring that the standards are adhered to, even if the standards have conflicts or are not clear. This appears to be more acute when agencies have regional licensees who may not be active diving instructors and are focused on revenue generation and not the maintenance of skilled instructors. There is very little, if any, evidence that leadership skills, traits or behaviours are taught anywhere in the diving industry as part of the formal agency staff or professional development processes. This impacts what happens in terms of safety culture development.
  • Finally, the focus on standards and rules aligns with the lowest level of the recognised safety culture models – Pathological from Hudson. Rules and standards do not create safety. Rules facilitate the discussion around what is acceptably safe, but they rarely consider the context surrounding the activities at the sharp end, i.e., dive centres and diving instructors and how they manage their businesses. These are grey areas. There is a difference between ‘Work as Imagined’ and ‘Work as Done,’ and individual instructors and dive centre managers must both ‘complete the design’ because the manuals and guides are generic, and manage the tension between safety, financial pressures, and people (or other resources) to maintain a viable business. Fundamentally, people create safety not through the blind adherence to rules, but through developed knowledge and reflecting on their experiences, and then sharing that knowledge with others so that they, too, may learn and not have to make the same mistakes themselves.

The proceeding discussion brings us to the main topics of this article, does the diving industry have a learning culture, and what is needed to support that learning culture?

What is a learning culture?

In the context of ‘safe’ diving operations, a learning culture could be defined as “the willingness and the competence to draw the right conclusions from its safety information system, and the will to implement major reforms when their need is indicated.” (Reason, 1997). Here we have a problem! 

‘Willingness…’

The industry is based around siloed operations: equipment manufacturers, training agencies, dive centres/operations, and individual instructors. Adopting a genuine learning approach means that the barriers must be broken down and conversations happen between and within the silos. This is very difficult because of the commercial pressures present. The consumer market is small, and there are many agencies and equipment manufacturers that are competing for the same divers and instructors. Also, agencies and manufacturers have competing goals. Agencies want to maximise the number of dive centres/instructors to generate revenue, and one of the ways of doing that is to maximise the number of courses available and courses that can be taught by individual instructors e.g., different types of CCR units. Manufacturers don’t want to realise the reputational risk because their equipment/CCR is involved in a fatal diving accident, but they also want to maximise their return on investment by making it available to multiple agencies and instructors. The higher-level bodies (WRSTC, RTC, and RESA) are made up of the agencies and manufacturers that will inherit the standards set, so there is a vested interest in not making too much change. Furthermore, in some cases, there is a unanimous voting requirement which means it is easy to veto something that impacts one particular agency but benefits many others.

‘Competence…’

This will be expanded in the section below relating to information systems as they are highly interdependent.

  • Halcyon Sidemount
  • Fourth Element
  • DIVE RITE

What safety information systems do we have in the diving community?

Training agencies each have their own quality assurance/control/management systems, with varying levels of oversight. This oversight is determined by the questions they ask, the feedback they receive, and the actions they take. These are closed systems and based around compliance with the standards set by the agency – sometimes those standards are not available to be viewed by the students during or after their class! Research has been carried out on some of this quality data, but it appears to have focused on the wrong part e.g., in 2018, a paper was published by Shreeves at al, which looked at violations outside the training environment involving 122 diving fatalities. While the data would have been available, a corresponding research project involving fatalities inside the training environment was not completed (or if it was, it wasn’t published in the academic literature).

As the ex-head of Quality Control of a training agency, I would have been more interested in what happened inside my agency’s training operations than what occurred outside, not from a retributive perspective, but to understand how the systemic failures were occurring. I also understand that undertaking such research would mean it would be open for ‘legal discovery’, and likely lead to the organisation facing criticism if a punitive approach was taken rather than a restorative one.

Safety organisations like Divers Alert Network collect incident data, but their primary focus is on quantitative data (numbers and types of incidents), not narrative or qualitative data – it is the latter that helps learning because we can relate to it. The British Sub Aqua Club produce an annual report, but there is very limited analysis of the reported data, and there does not appear to be any attempt made to look at contributory or influential factors when categorising events. The report lists the events based on the most serious outcome and not on the factors which may have influenced or contributed to the event e.g., a serious DCI event could have been caused by rapid ascent, following an out-of-gas situation, preceded by a buddy separation, and inadequate planning. The learning is in the contributory factors, not in the outcome. In fairness, this is because the organizations do not have to undertake more detailed investigations, and because the information isn’t contained in the submitted reports.

Research from 2006 has shown that management in organisations often want quantitative data, whereas practitioners want narrative data about what happened, how it made sense, and what can be done to improve the situation. Statistical data in the diving domain regarding safety performance and the effectiveness of interventions e.g., changes to the number of fatalities or buoyancy issues is of poor quality and should not be relied upon to draw significant conclusions.

What is required to populate these systems?

There are several elements needed to support a safety information system.

  • Learning-focused ‘investigations’.
  • Competent ‘investigators’.
  • Confidential and collaborative information management and dissemination systems.
  • Social constructs that allow context-rich narratives to be told.

Learning-focused ‘investigations’. The diving industry does not have a structured or formal investigation or learning process, instead relying on law-enforcement and legal investigations. Consequently, investigations are not focused on learning, rather they are about attributing blame and non-compliance. As Sidney Dekker said, “you can learn or blame; you can’t do both”. The evidence that could be used to improve learning e.g., standards deviations, time pressures, adaptations, poor/inadequate rules, incompetence, and distractions… are the same elements of data that a prosecution would like to know about to hold people accountable. Rarely does the context come to the fore, and it is context that shapes the potential learning opportunities. “We cannot change the human condition, but we can change the conditions in which humans work.” (James Reason). Rather than asking ‘why did that happen’ or even ‘who was to blame’, we need to move to ‘how did it make sense to do what they did’. ‘Why’ asks for a justification of the status quo, ‘how’ looks at the behaviour and the context, not the individual.

Competent ‘investigators’. As there isn’t any training in the diving domain to undertake a learning-focused investigation, we shouldn’t be surprised that the investigations focus on the individual’s errant behaviour. Even those ‘investigations’ undertaken by bodies like DAN, the NSS-CDS Accident Committee or the BSAC do not involve individuals who have undertaken formal training in investigations processes or investigation tools. A comprehensive learning review is not quick, so who is going to pay for that? It is much easier to deflect the blame to an individual ‘at the sharp end’ than look further up the tree where systemic and cultural issues reside. The education process for learning-focused investigations starts with understanding human error and human factors. The Essentials class, 10-week programme, and face-to-face programmes provide this initial insight, but the uptake across the industry, at a leadership level, is almost non-existent. Four free workshops are planned for Rebreather Forum 4.0 to help address this.

Confidential information management system. Currently, no system allows the storage of context-rich diving incident data outside the law-enforcement or legal system in a manner that can be used for learning. After discussions with senior training agency staff, it appears that as little as possible is written down following an incident. When it is, it is shared with the attorney to enable the ‘attorney-client’ privilege to be invoked and protected from discovery. If internal communications occur via voice, then the potential learning is retained in the heads of those involved but will fade over time. Furthermore, if they leave that role or organisation, then the information is almost guaranteed to be lost.

  • DIVE RITE
  • Halcyon Sidemount
  • Fourth Element

Social Constructs: Two interdependent elements are needed to support learning: psychological safety and a “Just Culture.” With the former, the majority of modern research strongly suggests that it is the presence of psychological safety that allows organisations to develop and learn (Edmondson, 1999). Edmondson describes numerous case studies where organisational and team performance was improved because incidents, problems, and near-misses were reported. Paradoxically, the more reports of failure, the greater the learning. It was not because the teams were incompetent; they wanted to share the learning and realised that they could get better faster with rapid feedback. They also knew that they wouldn’t be punished because psychological safety is about taking an interpersonal risk without fear of retribution or reprisal – this could be speaking up, it could be challenging the status quo, it could be saying “I don’t know”, or it could be about trying something new and coming up with an unexpected outcome.

The second requirement is a Just Culture which recognises that everyone is fallible, irrespective of experience, knowledge, and skills. This fallibility includes when rules are broken too, although sabotage and gross negligence (a legal term) are exceptions. Neither a Just Culture nor psychological safety are visible in the diving industry, although some pockets are present. To support psychological safety (proactive/prospective) and a Just Culture (reactive), there is a need for strong, demonstrable leadership:

  • Leaders who have integrity – they walk the talk.
  • Leaders who show vulnerability – talking about their own mistakes including the context and drivers; leaders who want to look at organisational issues inside their own organisation – not just point fingers at others problems.
  • Leaders who recognise that human error is only the starting point to understand something going wrong, not the end.

‘…the will to implement major reforms…’

This is probably the hardest part because learning involves change. Change is hard. It costs cognitive effort, time, and money, and this has an impact on commercial viability because of the need to generate new materials, to educate instructor trainers/instructors and divers about the change and do it in multiple languages. Unless there is a major external pressure, e.g., the insurance companies threaten to withdraw support, things are unlikely to change because there aren’t enough people dying in a single event to trigger an emotional response for change. For example, in the General Aviation sector in the US approximately 350 people die each year, but if these deaths happened in airliners, it would mean two to three crashes per year, and this would be considered unacceptable.

In 2022, more than 179 people died diving in the US. (personal communications with DAN)

The most radical changes happen when double-loop learning is applied.

NASA did not learn from the Challenger disaster because it focused on single-loop learning, and when Columbia was lost, the investigation unearthed a lack of organisational learning i.e., double-loop learning. Chapter 8 from the Columbia Accident Investigation Board provides many parallels with the diving industry. The recent changes to PADI drysuit training standards following a fatal dive on a training course provide an example of single-loop learning – fix the ‘broken instructor’ and clarify course training requirements. The double-loop learning approach would be to look at self-certification and the wider quality management across the agency/industry; however, such an approach has significant commercial disadvantages across the board.

Creating a Learning Culture

The previous paragraphs talk about many of the issues we’ve got, but how do we improve things?

  1. Move to using a language that is learning-based, not ‘knowing’-based. This video from Crista Vesel covers the topic relatively quickly. This includes not using counterfactuals (could have, should have, would have, failed to…) which are informed by hindsight bias. Fundamentally, counterfactuals tell a story that didn’t exist.
  1. Look to local rationality rather than judging others. Move from who (is to blame) and ‘why did you do that?’, to ‘how did it make sense for you to do that?’. Separate the individual from the actions/behaviours and stop applying the fundamental attribution bias where we believe the failure is due to an individual issue rather than the context.
  1. Look to break down the barriers between the silos and share information. Ultimately, the stakeholders within the diving community should be looking to create a safe diving environment. Throwing rocks and stones at each other for ‘incompetence’ is not going to help.
  1. Adopt the Five Principles of Human and Organisational Performance as outlined in this blog.
  1. Build ‘If Only…’ or something produced for the recreational market, into training programmes at the instructor trainer, instructor, and diver level. This way the culture can slowly change by telling context-rich stories that have ‘stickiness’. However, this requires a fundamental shift in terms of how stories are told and how risk is portrayed in the diving industry.
  1. Finally, recognise we are all fallible. Until we accept that all divers are fallible and are trying to do the best they can, with the knowledge they have, the money they have, the resources they have, the skills they’ve acquired, and the drivers and goals they are facing, then we are unlikely to move forward from where we are, and we’ll keep choosing the easy answer: ‘diver error’.

DIVE DEEPER

InDEPTH: Examining Early Technical Diving Deaths: The aquaCORPS Incident Reports (1992-1996) by Michael Menduno

InDEPTH: The Case for an Independent Investigation & Testing Laboratory by John Clarke

Gareth Lock has been involved in high-risk work since 1989. He spent 25 years in the Royal Air Force in a variety of front-line operational, research and development, and systems engineering roles which have given him a unique perspective. In 2005, he started his dive training with GUE and is now an advanced trimix diver (Tech 2) and JJ-CCR Normoxic trimix diver. In 2016, he formed The Human Diver with the goal of bringing his operational, human factors, and systems thinking to diving safety. Since then, he has trained more than 450 people face-to-face around the globe, taught nearly 2,000 people via online programmes, sold more than 4,000 copies of his book Under Pressure: Diving Deeper with Human Factors, and produced “If Only…,” a documentary about a fatal dive told through the lens of Human Factors and A Just Culture.

Continue Reading

Trending