This episode explores why experienced divers still die in situations that seem predictable, using the tragic 2026 Maldives cave accident as a starting point. It looks at how outcome bias, the normalisation of deviance, nitrogen narcosis, group dynamics, and silent drift can gradually erode safety margins without divers realising it. Rather than focusing on individual mistakes, the discussion explains how everyday decisions, accepted norms, and human psychology combine to create risk over time. It also examines what divers, teams, and the wider diving community can do to recognise these patterns, challenge unsafe habits, encourage open communication, and build a culture that learns from accidents instead of simply accepting them as bad luck.

Original blog: https://www.thehumandiver.com/post/we-know-and-we-say-nothing

1. Concept formalised by Baron, J. & Hershey, J. C., "Outcome bias in decision evaluation," Journal of Personality and Social Psychology 54 (1988), p. 569-579. PDF available: https://www.sas.upenn.edu/~baron/papers/outcomebias.pdf
2. Vaughan, D., The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA, University of Chicago Press, 1996. Publisher page: https://press.uchicago.edu/ucp/books/book/chicago/C/bo22781921.html
3. Lock, G., Under Pressure: Diving Deeper with Human Factors (2019); see also The Human Diver (https://www.thehumandiver.com) and the documentary If Only… (https://www.thehumandiver.com/ifonly).
4. First systematic experimental demonstration: Behnke, A. R., Thomson, R. M. & Motley, E. P., "The psychologic effects from breathing air at 4 atmospheres pressure," American Journal of Physiology 112(3), 1935, p. 554-558. DOI: https://doi.org/10.1152/ajplegacy.1935.112.3.554
5. For an overview, see Nitrogen Narcosis In Diving on StatPearls (NCBI/NIH): https://www.ncbi.nlm.nih.gov/books/NBK470304/; and Clark, J. E., Moving in extreme environments: inert gas narcosis and underwater activities, Extreme Physiology & Medicine 3 (2014), which establishes that narcosis directly contributes to up to 6% of diving deaths — free full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4337274/
6. Hamilton, K., Laliberté, M. F. & Fowler, B., "Dissociation of the behavioral and subjective components of nitrogen narcosis and diver adaptation," Undersea & Hyperbaric Medicine 22(1), March 1995, p. 41-49 (PMID 7742709): https://pubmed.ncbi.nlm.nih.gov/7742709/

Decision biases, normalisation of deviance, human factors

• Baron, J. & Hershey, J. C., "Outcome bias in decision evaluation," Journal of Personality and Social Psychology 54 (1988), p. 569-579. PDF: https://www.sas.upenn.edu/~baron/papers/outcomebias.pdf
• Vaughan, D., The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA, University of Chicago Press, 1996. Publisher page: https://press.uchicago.edu/ucp/books/book/chicago/C/bo22781921.html
• Lock, G., Under Pressure: Diving Deeper with Human Factors, 2019. The Human Diver: https://www.thehumandiver.com. Documentary If Only…: https://www.thehumandiver.com/ifonly

Physiology of narcosis

• Behnke, A. R., Thomson, R. M. & Motley, E. P., "The psychologic effects from breathing air at 4 atmospheres pressure," American Journal of Physiology 112(3), 1935, p. 554-558. First systematic experimental demonstration of the narcotic effects of compressed air at depth. DOI: https://doi.org/10.1152/ajplegacy.1935.112.3.554
• Kirkland, P. J., Mathew, D., Modi, P. & Cooper, J. S., Nitrogen Narcosis In Diving, StatPearls (NCBI/NIH), last updated 2023: https://www.ncbi.nlm.nih.gov/books/NBK470304/
• Clark, J. E., "Moving in extreme environments: inert gas narcosis and underwater activities," Extreme Physiology & Medicine 3 (2014). Free full text via PMC: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4337274/
• Hamilton, K., Laliberté, M. F. & Fowler, B., "Dissociation of the behavioral and subjective components of nitrogen narcosis and diver adaptation," Undersea & Hyperbaric Medicine 22(1), March 1995, p. 41-49. PMID 7742709: https://pubmed.ncbi.nlm.nih.gov/7742709/

Diving accident research

• Divers Alert Network, Annual Diving Reports (long series, 1988 to 2021). Full collection consultable online: https://www.ncbi.nlm.nih.gov/books/NBK481542/
• Exley, S., Basic Cave Diving: A Blueprint for Survival, National Speleological Society — Cave Diving Section, Branford (FL), 1979. Official NSS-CDS PDF: https://nsscds.org/wp-content/uploads/2018/05/Blueprint-for-Survival.pdf
• Buzzacott, P., Zeigler, E., Denoble, P. & Vann, R., "American Cave Diving Fatalities 1969-2007," International Journal of Aquatic Research and Education 3(2), 2009, p. 162-177. Free full text: https://scholarworks.bgsu.edu/ijare/vol3/iss2/7/
• Potts, L., Buzzacott, P. & Denoble, P. J., "Thirty years of American cave diving fatalities," Diving and Hyperbaric Medicine 46(3), September 2016, p. 150-154. PMID 27723015: https://pubmed.ncbi.nlm.nih.gov/27723015/

Tags: THD-English| THD-Learning, Incidents & Just Culture

This episode explores how a restorative just culture can help the diving community respond to incidents in a way that promotes learning rather than blame. Instead of focusing only on who broke the rules, it looks at who was harmed, what they need, and how trust can be rebuilt while addressing the wider conditions that contributed to the event. The discussion covers the impact on everyone involved, the role of accountability, compassion, and forgiveness, and why repairing systems is more effective than simply punishing individuals. It also introduces Professor Sidney Dekker's Restorative Just Culture Checklist as a practical tool for turning difficult events into opportunities for meaningful learning and safer diving.

Original blog: https://www.thehumandiver.com/post/2026-hfid-conference-what-did-you-miss

Tags: THD-English| THD-Education & Content Type| THD-HFiD-Conference

This episode explores the difference between a retributive approach to diving incidents, which focuses on blame and punishment, and a restorative just culture, which focuses on learning, repair, and preventing future harm. It explains how incidents affect not only those directly involved but also instructors, organisations, and the wider diving community, and argues that real accountability means understanding what happened, supporting everyone affected, rebuilding trust, and fixing the conditions that allowed the event to occur. The discussion also introduces Professor Sidney Dekker's Restorative Just Culture Checklist as a practical tool for helping individuals and organisations move from blame to meaningful learning and lasting improvement.

Original blog: https://www.thehumandiver.com/post/restorative-just-culture

Links: The PDF checklist: https://drive.google.com/file/d/1Vkg0o4Fc8XWsAul-mkXNqD5lwokQ0ntP/view?usp=sharing

Tags: THD-English| THD-Education & Content Type

This episode explores an important distinction that is often missed when discussing diving incidents: the difference between a cause, a reason, and an excuse. A cause explains what contributed to an event, a reason explains why a person's actions made sense to them at the time, and an excuse uses those reasons to avoid accountability. Understanding these differences helps us learn from accidents without simply assigning blame or letting people off the hook. The discussion shows why complex incidents usually have many interacting causes, why understanding local decision-making is essential for improving safety, and how separating learning from punishment leads to better conversations, stronger investigations, and safer diving for everyone.

Original blog: https://www.thehumandiver.com/post/cause-reason-excuse

Links: Accountability blog: https://www.thehumandiver.com/post/we-want-accountability

RaDonda Vaught case: https://www.thehumandiver.com/post/the-structure-is-normal-the-scale-is-not

Stop rules blog: https://www.thehumandiver.com/post/why-investigations-stop-where-they-stop

Richard Cook’s diagram: https://www.thehumandiver.com/post/joining-dots-is-easy-if-you-know-the-outcome

More about the RaDonda Vaught case: https://humanfactors101.com/2022/05/08/is-human-error-a-crime/

The eight question review: https://www.thehumandiver.com/post/eight-questions-about-maldives-accident

“Learning” the same lessons: https://www.thehumandiver.com/post/why-does-nothing-change

Tags: THD-English| THD-Learning, Incidents & Just Culture

This episode explores why accident investigations often stop long before they uncover the full picture. Drawing on research from safety science, it argues that the “cause” of an incident is not simply discovered—it is shaped by who is investigating, what they are able to change, and what explanations their community accepts. In diving, investigations often focus on the actions of individual divers or instructors because these are the easiest problems to address, while deeper issues such as organisational culture, commercial pressures, and industry practices are left unexplored. The episode examines how different people can interpret the same event in very different ways, why every investigation helps shape the community’s understanding of safety, and why asking “Why did the investigation stop here?” can lead to far richer learning than simply accepting the reported cause.

Original blog: https://www.thehumandiver.com/post/why-investigations-stop-where-they-stop

Links: The most complete data on diving fatalities from 2008: https://pubmed.ncbi.nlm.nih.gov/19175195/

Blog exploring the purposes of running an investigation: https://www.thehumandiver.com/post/what-is-the-purpose-of-an-investigation

LFEO program: https://www.thehumandiver.com/lfeo

HFiD conference: https://www.hf-in-diving-conference.com/

What you look for is what you find: https://doi-org.ludwig.lub.lu.se/10.1016/j.ssci.2009.01.004

What you find is what you fix: https://doi-org.ludwig.lub.lu.se/10.1016/j.aap.2010.07.003

Blog about agency/organisation standards: https://www.thehumandiver.com/post/beyond-the-floor

Speaking truth to power: https://www.thehumandiver.com/post/when-im-fine-isnt-true

Structural conditions that produce decisions: https://www.thehumandiver.com/post/the-structure-is-normal-the-scale-is-not

Other references:

Blazsin, H. & Guldenmund, F. (2015). The social construction of safety: Comparing three realities. Safety Science, 71, 16–27.

Lundberg, J., Rollenhagen, C. & Hollnagel, E. (2009). What-You-Look-For-Is-What-You-Find — The consequences of underlying accident models in eight accident investigation manuals. Safety Science, 47(10), 1297–1311.

Lundberg, J., Rollenhagen, C. & Hollnagel, E. (2010). What you find is not always what you fix — How other aspects than causes of accidents decide recommendations for remedial actions. Accident Analysis and Prevention, 42, 2132–2139.

Rasmussen, J. (1990). Human error and the problem of causality in analysis of accidents. Philosophical Transactions of the Royal Society of London B, 327, 449–462.

Rochlin, G. I. (1999). Safe operation as a social construct. Ergonomics, 42(11), 1549–1560.

Shreeves, K., Buzzacott, P., Hornsby, A., & Caney, M. (2018). Violations of safe diving practices among 122 diver fatalities. Int. Marit. Health, 69(2), 94–98. https://doi.org/10.5603/imh.2018.0014

van der Schaaf, T. W., Lucas, D. A. & Hale, A. R. (1991). Near miss reporting as a safety tool. Butterworth-Heinemann.

Tags: THD-English| THD-Learning, Incidents & Just Culture

This episode explores why diving accidents are so often explained by individual mistakes instead of the wider conditions that made those mistakes possible. Using the case of a fatal medication error in healthcare alongside the recent Maldives cave diving tragedy, it examines how hindsight, blame, and our natural tendency to focus on people rather than systems can prevent meaningful learning. The discussion highlights how unsafe practices can become normal when they repeatedly appear to work, and why serious accidents often reveal long-standing weaknesses that existed long before the final event. Rather than asking "Who is at fault?", the episode argues that the better question is "What conditions made these decisions seem reasonable at the time?"—because understanding those conditions offers the best chance of preventing similar tragedies in the future.

Original blog: https://www.thehumandiver.com/post/the-structure-is-normal-the-scale-is-not

Links: Martin Anderson’s write-up: https://humanfactors101.com/2022/05/08/is-human-error-a-crime/

Andrzej Gornicki’s Eight Question Review: https://www.thehumandiver.com/post/eight-questions-about-maldives-accident

Gareth’s blog about accountability: https://www.thehumandiver.com/post/we-want-accountability

Assumptions and worn paths: https://www.thehumandiver.com/post/why-rules-get-broken

Consensus is because people don’t want to disagree: https://www.thehumandiver.com/post/beyond-the-floor

Conditions produce outcomes: https://www.thehumandiver.com/post/what-conditions

Useful illegality in action: https://www.thehumandiver.com/post/why-rules-get-broken

Tags: THD-English| THD-Learning, Incidents & Just Culture

This episode explores why rule-breaking in diving is often more complicated than simply “breaking the rules.” It looks at the difference between shortcuts that organisations quietly depend on to keep operating and personal shortcuts taken for convenience or ego. Through real-world examples, the discussion explains how hindsight can unfairly turn system-wide problems into individual blame after an incident occurs. The episode also examines why teams often stay silent when they notice problems, how social pressure affects decision-making, and why genuine learning requires understanding the reality of how diving actually works rather than relying on simple explanations. Ultimately, it challenges divers, instructors, and leaders to recognise the difference between necessary adaptations and risky personal shortcuts before something goes wrong.

Original blog: https://www.thehumandiver.com/post/why-rules-get-broken

Links: Blog about how conditions shape actions: https://www.thehumandiver.com/post/what-conditions

Master thesis about storytelling to learn: https://www.thehumandiver.com/post/msc-part-1-the-problem-space

Guide to speaking truth to power: https://www.thehumandiver.com/resources

Tags: THD-English| THD-Learning, Incidents & Just Culture

This episode examines the deaths of five Italian divers in the Maldives and a Maldivian military diver who later died during the recovery operation, using the tragedy to explore how Just Culture approaches accidents in high-risk environments. Rather than rushing to blame individuals, the discussion walks through the Eight-Question Review framework, which looks first at the wider system: authority, procedures, training, resources, organisational culture, operational norms, and the pressures influencing decisions. The episode highlights how experienced scientific divers can still face hidden competence gaps when moving into technical cave environments, how commercial and research pressures can shape risk-taking, and how safety rules may drift away from everyday practice over time. It also explores the dangers of hindsight bias and why meaningful investigations must focus on understanding how decisions made sense to those involved at the time, not simply judging outcomes after the fact. The central message is that accidents rarely come from one bad decision alone, but from interacting conditions within a wider system—and that real learning only happens when we are willing to ask difficult questions before assigning blame.

Original blog: https://www.thehumandiver.com/post/eight-questions-about-maldives-accident

Links: Blog about the Chac Mool deaths: https://www.thehumandiver.com/post/chac-mool-triple-diving-fatality

Further reading on The Human Diver:

Change your Language, Change the World

They Lost Situation Awareness

The Eight-Question Review — LFEO course

Tags: THD-English| THD-Learning, Incidents & Just Culture

This episode reflects on the tragic deaths of five Italian divers in the Maldives and a Maldivian military diver who died while trying to recover them, using the event to explore what real accountability should look like after a diving accident. Rather than rushing to blame or making assumptions based on limited information, the discussion challenges the diving community to resist quick judgement and focus instead on understanding the conditions, decisions, and systems that may have shaped the outcome. It examines the difference between backward-looking accountability, which seeks someone to blame, and forward-looking accountability, which asks better questions about training, equipment, oversight, environmental conditions, and the support given to those involved in both the original dive and the recovery effort. At a time when facts are still emerging, the episode argues that meaningful learning begins with humility, patience, and a commitment to understanding what really happened—because only then can the diving community improve and better protect those who dive and those asked to rescue others.

Original blog: https://www.thehumandiver.com/post/we-want-accountability

Tags: THD-English| THD-Learning, Incidents & Just Culture

This episode challenges the instinct to explain diving accidents by focusing only on individual mistakes or broken rules. Instead, it explores how social, cultural, organisational, and environmental conditions shape the decisions divers make, even when those decisions seem irrational in hindsight. Using recent diving incidents as examples, the discussion highlights how behaviour that appears risky often made sense to those involved at the time, influenced by pressures such as authority, identity, time, and the expectation to “get the job done.” The episode introduces the PETTEOT framework—Person(s), Environment, Tasks, Tools and Technology, External Influences, Organisation, and Time—as a way to better understand how different parts of the diving system interact to create both success and failure. By moving beyond blame and examining the wider system, divers, instructors, and leaders can uncover the hidden conditions that shape performance and learn where meaningful improvements can be made, helping the community become better than yesterday.

Original blog: https://www.thehumandiver.com/post/what-conditions

Links: Blog about LEODSI and PETTEOT: https://www.thehumandiver.com/post/what-is-leodsi-petteot

Tags: THD-English| THD-Learning, Incidents & Just Culture