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Errors In Diving Can Be Useful For Learning— ‘Human Error’ Is Not!

Errors are normal and can help us learn as long as we understand the kind of error we made, and how it made sense for us at the time. Conversely, simply attributing the cause of a diving accident to ‘human error’ is practically useless. Here Human Factors Coach Gareth Lock examines various types of errors and violations, and importantly the influence of the system in which they operate, and explains why simply citing ‘human error’ ain’t enough.



Text by Gareth Lock. Images by G. Lock unless noted. The Human Diver is a sponsor of InDepth.

The title of this article might appear to be an odd statement because there is a conflict; however, that conflict is intentional. This is because there is a difference between the term “error,” which can help us learn, and the attribution which people apply to the cause of an accident as ‘human error’ which doesn’t help anyone. In fact, if you see ‘human error’ or ‘diver error’ or ‘human factors’ as the cause of an adverse event, then the investigation stopped too early, and the learning opportunities will be extremely limited.

What is an error?

A few simple definitions might be

  • the outcomes from a system that didn’t deliver the expected results
  • an unintended deviation from a preferred behaviour
  • something that is not correct; a wrong action or statement

To a certain extent, the precise definition of an error isn’t that important because whatever definition we use, we must recognise that ‘errors’ are never the cause of an accident, incident, or an adverse event, rather they are indicative of a weakness or failure somewhere in the wider system. If you are wondering what ‘system’ means in this context, it will be covered in the next section.

One of the key points to recognise is that an error can only be defined after an event. The reason for this is because if we knew we were going to make a mistake, a slip, or have a lapse, then we would have done something about it to prevent the negative behaviour/event from occurring! The terms mistake, slip, and lapse were specifically used as these are recognised terms in the science of human factors to describe the different types of variability in our performance.

Some Definitions

  • A mistake is where you’ve done the ‘wrong’ thing but thought it was correct. Examples of this could be that training materials have changed but you’re teaching the old skill because you weren’t aware of the change, entering a wreck via the ‘wrong’ doorway thinking it was the correct one or surveying the ‘wrong’ part of the reef as some cues/clues for the location had been misinterpreted.
  • A slip is an unintended action. This could be cross-clipping a bolt snap, writing the wrong gas analysis figures down because you transposed two numbers, or putting the diver tally number on the wrong peg on a boat board.
  • A lapse is when we forget something. This could be forgetting the additional weight pouch needed for saltwater, not doing up the drysuit zip, or not going through the process to count all the divers back on the boat.
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By breaking ‘errors’ down into these categories, we can develop mitigations to reduce the likelihood of them occurring on dives. For mistakes, buddy checking, co-teaching, QC/QA processes and debriefs all help us recognise when something isn’t quite right. For slips, we can design something so that it is harder to do the wrong thing. For lapses, we can use a checklist, buddy check, or physical prompt/modification to reduce the likelihood that critical items are not forgotten before it is too late. We can also look to modify the ‘system’ so that we are less likely to make an error, or if we do, we catch it before it is critical. 

There is also an additional classification of errors called ‘violations’ which is where a rule of some sort is present and has not been followed. ‘Violations’ are also broken down into different categories too.

Photo by Barbara Leatham
  • Situational violation is where the context led to breaking the rule being the ‘obvious’ answer. This could be where a dive center manager tells an instructor to break the standards for commercial reasons or risk losing their job, or where a diver forgets their thermal undergarments and dives anyway because of time/money invested, or a wreck is penetrated without a line because the visibility appears fine.
  • Routine violation is where it is normal to break the rules and potentially where it is socially more difficult to comply. Examples include not using written pre-dive checklists on CCR because no one else does, not analysing gas prior to a dive because no one else does, going below gas minimums because the boat crew make fun of coming up with ‘too much gas’.
  • Exceptional violation is where breaking the rule is potentially safer than compliance. This might be rescuing someone below the MOD of the gas being breathed or going below gas minimums because you were cutting someone from an entanglement.
  • Recklessness is where there is no thought or care for the outcome. In hindsight, many think this is present in some cases. However, in my opinion, if divers genuinely thought that their dive would end up with a serious injury or fatality, they wouldn’t do it. As such, there are weaknesses in education or self-awareness.

With the exception of recklessness, violations also provide opportunities for organisational learning. What is it about the rule that meant it was harder to follow? If rules are consistently being broken, it is not likely a person thing, but rather a situational or contextual thing that needs to be addressed. Investigations shouldn’t stop at the rules that were broken, as it is likely that they were broken before, and an adverse event didn’t happen then.

Terms like ‘loss of situational awareness’, ‘complacency’ and ‘poor teamwork’ are just other ways of expressing a general term like ‘human error’. 

All these types of ‘errors’ within the system provide learning opportunities, but only if they are examined in detail and reflected upon to understand what was going on at the time.

What do you mean by ‘system’?

A system is a mental construct or idea used to describe how something works in an environment. In human factors terms, this is where humans are involved with technology, with paperwork, with processes, within physical, social, and cultural environments, and with other people. A diver who is on a boat using open circuit SCUBA about to enter the water with their teammate and dive a wreck in 50 m/170 ft is part of a system. The system they are within contains:

  • Equipment designed and tested against certain standards.
  • Compressed gas from a fill station which has protocols to follow making it safe to breathe.
  • Training from multiple instructors using training materials from different agencies following high-level standards from a body like the RSTC or RTC, each of which has a QA/QC process in place.
  • Protocols from the boat’s captain based on national and local maritime requirements.
  • A dive computer that has decompression algorithms developed and refined over time.
  • A cultural and social environment that influences how to behave in certain circumstances.
  • A physical environment consisting of surface and underwater conditions.
  • A wreck description that was drawn on a whiteboard on the boat, with a brief delivered by a guide explaining what is where and when to end the dive.
  • Personal and team goals/drivers/constraints which have to be complied with or are shaping decisions.
  • Multiple other divers and dive teams on the same boat who have their own needs, training, goals/drivers/constraints.
  • Human bodies with their own individual physical, physiological and psychological requirements and constraints.
  • The boat crew and their competencies and experience.

This list is by no means exhaustive but gives you an idea of all the ‘things’ that go into a system and those ‘things’ that might have weaknesses within them. Addressing these weaknesses and developing strengths are respectively what the science of human factors and resilience engineering are about.

When something goes wrong, why shouldn’t we use ‘human error’ as a cause?

There are a few problems with the term ‘human error’ as a cause.

  • Firstly, it is a bucket that we can put all the different sorts of performance variability into without understanding what we can do to prevent future events. We will all make errors, so saying to divers ‘be careful’, ‘pay more attention’, or ‘be safe’ doesn’t help identify the factors that lead to the errors. These are the error-producing or latent conditions that are always there but not always together and don’t always lead to a problem. e.g., time pressures, incomplete briefing, equipment modifications, equipment serviceability, inadequate communications, flawed assumptions, and so on.
  • Secondly, due to the fundamental attribution bias, we tend to focus on the performance of individual divers or instructors, rather than look at the context, the wider system, in which they were operating. As there isn’t a structured way of investigating adverse events in diving industry (coming soon!) or even using a standard framework to work out ‘how it made sense to those involved’, divers often jump to the conclusion that the cause was a just part of being a human and was ‘human error’ or ‘the human factor’. This is far from the case as you can see in the ‘If Only…’ documentary.
  • Finally, adverse events like accidents, incidents, and near-misses are the outcomes of interactions within a system, and we can’t deconstruct the problem to single failures of individuals, hoping to ‘fix’ them. If that was the case and the problem was just down to errant individuals, we’d have far more adverse events than we do because people are broadly wired the same way. Humans, as well as being a critical factor when it comes to failure, are also the heroes in many cases when the system they are within doesn’t have all of the information provided to be ‘safe’. As such, we need to look at the wider system elements and their relationships to look at both success and failure.

We want divers to make errors…

Conversely, there are times when we don’t mind people making errors (slips, lapses, mistakes, and some types of violations) during a training course or even during exploration. In fact, in some cases, it is to be encouraged. The reason is that errors provide opportunities for learning. If we never make an error, we will never improve. Innovation means we are pushing boundaries against uncertainty, and with uncertainty comes the possibility that we end up with an outcome that wasn’t expected or wanted. By using trial and error, we have a better idea of where the boundary is. Self-discovery is one the most powerful learning tools we have because there is personal buy-in. Errors in training also help us solve problems in the real world, because the real world rarely follows fixed boundaries, and it is much better to fail in the training environment where you have an instructor with you to provide a safety net. Note, the instructors have to have a high level of skills/experience to act as this safety net! 

Even when we don’t want divers or instructors to make errors, there will be times when things don’t go to plan. Experts are continually monitoring and adapting their performance, picking up small deviations and correcting them before they become a safety-critical event. This is why it is important to focus on and fix the small stuff before it snowballs and exceeds your capacity to manage the situation.

Fellow Human Diver instructor Guy Shockey uses the analogy of a Roomba (automated, robotic hoover) to explain this concept during his Fundamentals, Technical and Rebreather classes. The Roomba doesn’t know anything about its environment. However, over time, as it bounces its way around the house, it finds the locations of the walls, chair legs, table legs, doorways and other obstacles and creates a map of the boundaries. However, humans still have to help it when it comes to stairs as the top step doesn’t have a boundary, and it falls down! The ‘system’ solution is to put a ‘virtual wall’ in place so that the wall sensors can detect where the drops are. 

What we are looking to develop during training, fun diving, and exploration is resilience. This is the capacity to adapt our performance and skills to deliver positive results when situations are changing around us, even to the point where we have an adverse event, but fail safely. Resilience provides us with:

  • the ability to anticipate what might happen (positively and negatively),
  • the ability to identify and monitor the critical factors to ensure safety,
  • the ability to respond to what is going on around us, and finally,
  • the ability to learn from what has happened in the past and apply it to future dives.

Resilience is developed from direct experience and learning from others’ activities and outcomes. We shouldn’t just focus on learning from negative outcomes though, we also want to know what makes positive ones happen, too. 

Note, if instructors are only taught to follow a standard ‘script’ of what to do when, then when they or their students encounter something novel, they are more likely to have an unexpected outcome. That outcome might be ‘lucky’ (good) or ‘unlucky’ (bad). Experience helps stack the odds in our favour by building resilience. At an organisational level, sharing near misses and workarounds amongst instructors provides other instructors with this learned knowledge so that they are more resilient when they teach. Resilience doesn’t just exist at the individual level, it applies at the system level too.

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In Conclusion

Errors are normal, and they can help us learn as long as we understand what sort of error we made and how it made sense for us to do what we did. This reflection isn’t easy because it requires effort. It also requires us to understand how we create a shared mental model within our team of what is happening now and what is likely to happen in the future (the key goal of non-technical skills development programmes). 

We also need to understand the influence the system has on our behaviours and actions and look further back in time and space to see what else was present. Therefore, if we genuinely want to understand what led to the adverse events, we should spend time looking at what ‘normal’ looks like, the conditions that are normally present and what divers and instructors have to deal with, not just those that were present at the time of the adverse event. Accidents and incidents occur as deviations from normal, not just deviations from standards.

While ‘human error’ might be an easy bucket to throw the variability of human performance and its associated outcomes into, the attribution rarely improves safety or performance because it doesn’t look at the rationale behind the performance or the context associated with it. For that, we have to dig deeper and understand local rationality.

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 350 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.  


Risk-Takers, Thrill-Seekers, Sensation-Seekers, and … You?

It’s likely that many in our community no longer think of tech diving as a risky activity, or perhaps even appreciate how important taking risks may be to one’s personal health—let alone that of our species. Fortunately, InDEPTH’s copy editing manager Pat Jablonski dived deep into the origins, meaning, and benefits of regularly taking risks, and even offers a thrill-seeking quiz for your edgy edification. What have you got to lose?




by Pat Jablonski. Title photo courtesy of Katelyn Compton Escott.

“Life without risk is not worth living.” – Charles Lindbergh

What defines a risk? What is involved in taking a risk?

Difficult questions to answer, because something that feels risky to one person might be yawn-worthy to another. Risk taking, unscientifically, is something you do that gets your blood up, raises your heartbeat, awakens your senses, and makes you hyper-aware of your surroundings.

Surely we can agree that the Covid pandemic has added an unexpected level of risk to everyday life. Add poor drivers, mass shootings, contentious politics, global climate change, and many are left believing that meeting each day is risky enough. But that’s not true for people who identify as risk-takers or thrill-seekers.

“Everyone has a ‘risk muscle’. You keep in shape by trying new things. If you don’t, it atrophies. Make a point of using it once a day.” – Roger Von Tech

There are many activities that go to the trouble of defining the level of risk involved with a specific activity, and while that’s not the purpose of this article, you should know that scuba diving ranks fairly high on the risky behavior scale–higher than skydiving and rappelling. And, cave/wreck diving or freediving isn’t on any risk scale we could locate. We can assume it’s up there—near or at the top.

Fock A. Analysis of recreational closed-circuit rebreather deaths 1998–2010 Diving and Hyperbaric Medicine. 2013 Volume 43, No. 2. With the caveat that they are “best guess numbers,” Fock concluded that rebreather diving is likely 5-10x as risky as open circuit scuba diving, accounting for about 4-5 deaths per 100,000 dives, compared to about 0.4 to 0.5 deaths per 100k dives for open circuit scuba. This makes rebreather diving more risky than skydiving at .99/100k, but far less risky than base-jumping at 43 deaths/100k. The current belief is that rebreather diving has gotten safer.

Divers are a fairly small niche group for many reasons. One of them could involve the degree of danger associated with the sport. Answer this: Do dry land people ever ask you why you would want to take such a chance with your life in order to go where you weren’t meant to go? 

It’s a reasonable question, albeit a hard one to answer.

Photo courtesy of Glen Kwan

“A life without risk is a life unlived, my friend.” – Big Time Rush

Kevin Costner’s Waterworld aside, humans have (yet) to be born with gills or webbed toes. Still, there you are. You’ve spent unmentionable amounts of money. You’ve carved out a whole day, or maybe weeks, away from your to-do list. You’re suited up and look like an alien. You’re on a quest to explore the aquatic world where you’re able to breathe only with a cumbersome apparatus. You’re planning to explore inner space! You’re going to delve into that amazing realm that’s off limits to most people. 

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You may look all matter-of-fact, cool as a cucumber, another day at the office, but it’s a thrill, isn’t it? Inside, you’re a kid with butterflies in your tummy who’s getting away with something big and exciting. Okay, it’s true–you and your team are highly trained, your equipment is top-notch, every box is checked off, and you are behaving responsibly. However, you’d have to be in a coma to not realize that what you’re about to do is taking a risk. Who doesn’t know that people have died doing what you’re doing? Answer honestly: How much more exhilarating is the experience when you know it’s not a walk in the park? Our own Michael Menduno admitted that “the feeling of being more alive lasted for days” after a dive.

So, you’re a diver. Does that mean you’re a risk taker? A thrill seeker? A sensation seeker?

Let’s dive into that subject, first by taking a little quiz, shall we? 

Photo courtesy of SJ Alice Bennett

From A Death Wish to Life Is Precious

In the past, too many mental health professionals treated risky behavior like a disease in need of a cure, focusing on the negative side of risk, even using government funding to address risky behavior and stamp it out. 

Before that, Sigmund Freud might have even believed that thrill seekers had a death wish; in fact, it’s what was believed for many years. 

Modern-day science doesn’t support either theory.

“Only those who will risk going too far can possibly find out how far one can go.” – TS Elliot

For our purposes, we’re focusing on the positive aspects of taking chances, pushing boundaries, and seeking experiences that make life feel . . . more alive. Richer. Fuller. We want to examine what goes into the psyche of a person (like you?) who is enthusiastically willing to engage in an activity already identified as dangerous, possibly even by the people who are engaging in it, and hear what some experts on the subject have to say about such people.

Photo courtesy of Jen MacKinnon

The University of Michigan’s Daniel Kruger proposes that taking chances is a fundamental part of human nature going all the way back to our ancient ancestors—prehistoric humans who had to constantly put their safety on the line in their fight for survival. Think fighting off a wooly mammoth with a stick. Kruger believes we have consequently retained many of those same instincts today, and he believes that it’s a good thing. 

This writer, who is related to a major risk-taker, has always believed that heart-quickening experiences are essential for a well-lived life. I’m convinced and have long proposed that those pulse-pounding moments are often accompanied by a deepened understanding of and appreciation for one’s life—perhaps all life. And I’m happy to report that current science confirms that belief.

“If you are not willing to risk the unusual, you will have to settle for the ordinary.” – Jim Rohn

Dr. Kruger is one of the scientists who proposes that taking risks means “seeking that moment when life feels most precious.

This should not be news for you diving adventurers out there.

Nature vs. Nurture: Born That Way or Learned To Love Adventure

Another scientist, Marvin Zuckerberg, affirms the theory that risk taking is in our DNA. “Certain people have high sensation-seeking personalities that demand challenges and seek out environments that most people’s brains are geared to avoid.” I’ll go out on a limb and say that underwater caves or shipwrecks would qualify as environments most would avoid.

Dr. Cynthia Thompson, the researcher behind a 2014 study from the University of British Columbia, was early to look at the genetic factors that might make a person predisposed to participating in extreme sports, ones that are typically defined as activities where death is a real possibility. The results of her study revealed that risk-takers shared a similar genetic constitution, a genetic variant that influences how powerful feelings are during intense situations.

Photo courtesy of Steve Boisvert

Most scientists agree that personality is a complicated mix of genetic and environmental influences. The “nature vs. nurture” dilemma is alive and well. Dr. Thompson concluded that people who engaged in so-called high-risk sports were not impulsive at all, not reckless either. Instead, “they’re highly skilled masters of their discipline who take a very thoughtful approach to their sports.”

A study conducted in 2019 examined human boundaries, people who pushed them to their limits and beyond, and what made those people tick. Zuckerman labeled such people “sensation seekers” and defined them as “people who chase novel, complex, and intense sensations, who love experience for its own sake, and who may take risks to pursue those experiences.” Is that you?

“History is full of risk-takers. In fact, you could say that risk-takers are the ones who get to make history.” – Daniel Kruger

Other experts posit an alternate theory—one proposing that modern society in the age of seatbelts, guardrails, child-proof caps, safety precautions, laws, rules, and regulations has dulled the sense of survival. In other words, life has flattened out and no longer feels exciting, or risky. So, is one of the reasons we seek excitement because of boredom? 

Maslow’s Theory of Self-actualization

I don’t honestly know who was the first proponent of risk-taking being a positive thing, but the work of Abraham Maslow, the founder of humanistic psychology, was one of the first. Maslow became one of the most influential psychologists of the twentieth century, and he developed a theory of human motivation that advocates for “peak experiences.” Peak experiences are not attained without risk.

“One can choose to go back toward safety or forward toward growth. Growth must be chosen again and again; fear must be overcome again and again” – A Maslow

He proposed that, in addition to meeting basic needs, all humans from birth seek fulfillment in terms of what he called self-actualization—finding their purpose/being authentic. Self-actualization involves peak experiences—those life-altering moments that take us outside ourselves, make us feel one with nature, and allow us to experience a sense of wonder and awe. Maslow also believed that those who were able to have such peak experiences tended to seek them out rather than waiting for the next random occurrence. Hence the anticipation of the next dive?

“Do one thing every day that scares you.” – Anonymous

Photo courtesy of Adam Haydock

Out of Your Comfort Zone Into A World of Wonder

Psychologist Eric Brymer from Queenstown University of Technology in Brisbane, Australia, has spent years studying extreme athletes and has this to say: “They’re actually extremely well-prepared, careful, intelligent, and thoughtful athletes with high levels of self-awareness and a deep knowledge of the environment and of the activity.”

Recent research backs up what some extreme sports athletes have been saying for years, even if only to themselves.

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“What participants get from extreme sports is deeply transformational, a sense of connecting with a deep sense of self and being authentic, a powerful relationship with the natural world, a sense of freedom,” says Brymer. “They get a strong sense of living life to its fullest as if touching their full potential.”

Brymer’s comments mirror what Maslow, the founder of humanistic psychology, said back in the 1940s.

We’re not advocating for taking stupid chances (such as diving without proper training, or necessary precautions) and we don’t believe anyone reading this article does that. We simply intended to focus on the scientific evidence that supports adventurers—people who get a thrill from an activity that offers—as a bonus; a chance to feel awakened from the mundane and thrust into a world of wonder. 

Risk-takers and sensation- or thrill-seekers chase unique experiences. Often, those experiences bring awareness of important issues or increase essential knowledge about the planet we share. Many people overanalyze and dither when faced with an unfamiliar situation; they shy away from unsettling circumstances. Risk-takers face the unknown and trust themselves to prevail. Learning to scuba dive, for example, pushes people out of their comfort zone, takes them into a realm foreign and mysterious. Diving forces divers to pay complete attention to a task, to focus with laser-like precision in order to conquer misgivings, and to attain a skill that few others have. Confidence comes with accomplishment. Leadership emerges. Fear is overcome. 

Sensation-seekers see potential stressors as challenges to be met rather than threats that might defeat them. With action, resilience develops. High sensation-seekers report lower perceived stress, more positive emotions, and greater life satisfaction. Engaging in extreme activities brings them peace. 

What does it bring you?

Dive Deeper

Bandolier: Risk of dying and sporting activities

National Geographic: What Makes Risk Takers Tempt Fate? Recent research suggests that genetic, environmental, and personal factors can make people take on risky—even potentially fatal—challenges.

Healthday: Taking Risks By Chris Woolston HealthDay Reporter

Pat Jablonski heads up the copy edit team for InDEPTH. She is a blogger, a writer of stories, a retired tutor, English writing teacher, and therapist. She’s a friend, a wife, a proud mother and grandmother. She is also a native of Florida, having spent most of her life in Palm Beach County. She has a B.A. in English from FAU in Boca Raton and an M.S.W. from Barry University in Miami. She learned to swim in the ocean, a place she thinks of as home, but she doesn’t dive.

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