

Counter-Errorism in Diving: Applying Human Factors to Diving
Gareth Lock at The Human Diver
Human factors is a critical topic within the world of SCUBA diving, scientific diving, military diving, and commercial diving. This podcast is a mixture of interviews and 'shorts' which are audio versions of the weekly blog from The Human Diver.
Each month we will look to have at least one interview and one case study discussion where we look at an event in detail and how human factors and non-technical skills contributed (or prevented) it from happening in the manner it did.
Each month we will look to have at least one interview and one case study discussion where we look at an event in detail and how human factors and non-technical skills contributed (or prevented) it from happening in the manner it did.
Episodes
Mentioned books

Mar 29, 2025 • 5min
SH160: Outcomes are so sexy and attractive…
This episode dives into the critical role of human factors in safety, using a tragic aviation incident and its parallels in diving to illustrate how distractions, pressures, and systemic issues contribute to accidents. We explore how a Royal Air Force training film, "Distractions," highlighted the cumulative factors behind a hypothetical crash, emphasizing the need for shared responsibility in preventing errors. Similarly, the story of Brian Bugge's 2018 diving accident reveals the dangers of focusing solely on individual mistakes while overlooking the broader contributing factors. Accidents rarely result from a single error but emerge from a combination of conditions. By understanding these dynamics, we can better mitigate risks and improve safety in both aviation and diving.
Original blog: https://www.thehumandiver.com/blog/outcomes-are-so-sexy
Links: “If Only” Documentary: https://www.thehumandiver.com/ifonly
Tags: English, CCR, Checklists, Decision Making, Gareth Lock, If Only, Investigations, Rebreather

Mar 26, 2025 • 3min
SH159: The best is the enemy of the good
In this episode, a newly qualified Human Factors in Diving Instructor shares their journey of grappling with impostor syndrome and the challenges of teaching human factors to divers. Despite over a decade of diving instruction experience, they recount feeling inadequate compared to peers and doubting their knowledge, especially when students might view human factors as "common sense." Reflecting on the Dunning-Kruger effect, they explore how experts often underestimate their abilities because they understand the vastness of their field. Through conversations with peers and self-reflection, they learn to embrace the value they bring to the classroom and the importance of fostering curiosity in their students.
Original blog: https://www.thehumandiver.com/blog/the-best-is-the-enemy-of-the-good
Tags: English, Communications, Jenny Lord, Leadership, Teamwork

Mar 22, 2025 • 9min
SH158: Predictive Profiling & diving: “what deviates, deserves attention!”
This episode dives into the critical importance of recognizing deviations from the norm in diving, a concept rooted in situational awareness. Inspired by the 1972 attack at Lod Airport, Bart den Ouden draws parallels between how assumptions can blind us and the role of training and experience in diving. By understanding what “normal” looks like, divers can detect and respond to unexpected changes. We explore mental models, decision-making under pressure, and the value of learning skills the right way to build a strong foundation. Tune in to learn why paying attention to the small details can make all the difference underwater!
Original blog: https://www.thehumandiver.com/blog/predicitive-profiling
Links: Situational Awareness and Decision Making in Diving: https://gue.com/blog/situational-awareness-and-decision-making-in-diving/?fbclid=IwAR1Pq5eqIxWxcc0s1S2CoYefJgkWeXy_pUi8AsjQ8BoKSx-xKKXrLTPqleQ
Tags: English, Bart Den Ouden, Decision Making

Mar 19, 2025 • 8min
SH157: The Good, the Bad and the Ugly!
In this episode, we explore the pitfalls of blindly trusting technology through two cautionary tales—one about a GPS mishap in snowy Quebec and another about divers relying solely on their computers. Automation offers precision and convenience, but over-reliance can dull our awareness and problem-solving skills. We discuss how this applies to diving, where dive computers are invaluable but prone to errors if misconfigured or when they fail. Listeners will learn why it’s essential to combine technology with old-school skills, planning, and situational awareness to ensure safety. Embrace technology, but always have a backup plan!
Original blog: https://www.thehumandiver.com/blog/the-good-the-bad-the-ugly
Tags: English, Decision Making, Helene Pellerin, Situational Awareness

Mar 15, 2025 • 11min
SH156: CCR pre-dive checks and checklists are not always enough to prevent an equipment-based accident!
In this episode, we explore how safety in diving is not just about avoiding accidents but about building systems that can fail safely. Drawing on a real-life incident shared by Phil Short, we examine how a small technical issue—debris in a rebreather valve—could have escalated into a life-threatening situation during a cave dive. We highlight the critical role of technical preparation, situational awareness, and non-technical skills like teamwork, leadership, and communication in managing and recovering from unexpected challenges. By sharing these stories, we aim to help divers understand how to plan for failures and enhance safety through learning, reflection, and a chronic unease about what could go wrong.
Original blog: https://www.thehumandiver.com/blog/failing-safely-400m-back-in-a-cave
Links: How Safe is Your Diving blog: https://www.thehumandiver.com/blog/how-safe-is-your-diving
Tags: English, CCR, Decision Making, Gareth Lock, Leadership, Non-Technical Skills, Teamwork

Mar 12, 2025 • 11min
SH155: How safe is your diving?
In this episode, we dive into the concept of psychological safety and its critical role in diving and team performance. Psychological safety, defined as a shared belief that it's safe to take interpersonal risks, enables people to ask questions, make mistakes, contribute ideas, and challenge the status quo without fear of judgment or reprisal. Drawing on insights from experts like Amy Edmondson and Dr. Timothy Clark, we explore its four stages: inclusion, learner safety, contributor safety, and challenger safety, with a focus on how each stage impacts divers, instructors, and teams. From life-or-death scenarios to fostering innovation, creating a culture of psychological safety can improve decision-making, teamwork, and training outcomes. Tune in to learn how to build this essential skill in your diving and beyond.
Original blog: https://www.thehumandiver.com/blog/how-safe-is-your-diving
Links: If Only video: https://vimeo.com/382399090
Debrief guide: https://www.thehumandiver.com/debrief
Psychological Safety and Learning Behaviour in Work Teams: http://web.mit.edu/curhan/www/docs/Articles/15341_Readings/Group_Performance/Edmondson%20Psychological%20safety.pdf
High Performing Teams need Psychological Safety: https://liberationist.org/high-performing-teams-need-psychological-safety/
What Psychological Safety is not: https://qz.com/work/1470164/what-is-psychological-safety/
Tags: English, Communication, Decision Making, Gareth Lock, Just Culture, Leadership, Teamwork

Mar 8, 2025 • 9min
SH154: The Importance of Decision Making in Setting Goals: Ensuring “The Juice is worth the Squeeze”
In this episode, we explore the double-edged nature of goal setting—how it drives achievement but can also lead to risky decisions when pressure and commitment override safety and judgment. Using examples from mountaineering and advanced diving, including a personal story about a challenging CCR trimix course, we delve into the concept of "destructive goal setting." The discussion highlights how external pressures and an unwillingness to abandon goals can cloud decision-making, and emphasizes the importance of open communication, team empowerment, and stepping back to reassess whether "the juice is worth the squeeze."
Original blog: https://www.thehumandiver.com/blog/is-the-juice-worth-the-squeeze
Tags: English, Cognitive Biases, Decision Making, Guy Shockey

Mar 5, 2025 • 6min
SH153: Why ‘They should have’, ‘...could have’ or ‘I would have..’ do not improve diving safety
In this episode, we explore the concept of counterfactual reasoning—our tendency to imagine how incidents could have been avoided by different actions—and why it falls short in improving safety. While this type of hindsight helps us feel better by creating a sense of order, it doesn’t address the real-world conditions or decisions that led to the incident. Instead of asking, "Why didn’t they do Y instead of X?" we should ask, "How did doing X make sense to them at the time?" By focusing on what actually happened and understanding the context, we can uncover valuable insights to improve safety and decision-making in diving.
Original blog: https://www.thehumandiver.com/blog/counter-factuals
Tags: English, Cognitive Biases, Decision Making, Gareth Lock, Incident Analysis

Mar 1, 2025 • 16min
SH152: The Bend is Uninteresting...The Related Decisions Are Much More So
In this episode, we explore a personal account of a Gareth’s experience with decompression sickness (DCS) and the critical decision-making process that followed. The story dives into the internal monologue, biases, and stigmas surrounding DCS, highlighting how emotions and uncertainties influence risk-based decisions. We also examine industry practices, the importance of creating a psychologically safe culture for discussing incidents, and the need for better preparedness when things go wrong. This episode challenges listeners to reflect on their own decision-making and encourages a shift toward curiosity and learning in the diving community.
Original blog: https://www.thehumandiver.com/blog/the-bend-is-uninteresting-the-related-decisions-are-much-more-so
Links: PACE model: https://gcaptain.com/graded-assertiveness-captain-i-have-a-concern/
Prospect Theory: https://www.jstor.org/stable/1914185
Blog about Normalisation of Deviance: https://www.thehumandiver.com/blog/being-a-deviant-is-normal
Distancing through Differencing: https://www.researchgate.net/profile/David_Woods11/publication/292504703_Distancing_through_differencing_An_obstacle_to_organizational_learning_following_accidents/links/5742fb1808ae9ace8418b7ea/Distancing-through-differencing-An-obstacle-to-organizational-learning-following-accidents.pdf
Tags: English, Decision Making, Gareth Lock

Feb 26, 2025 • 9min
SH151: When the holes line up...
In this episode, we explore Professor James Reason's Swiss Cheese Model, which helps explain how incidents occur when multiple safety barriers fail at different levels within a system. We discuss how organizational, supervisory, and individual errors can combine to create accidents, and how the holes in these barriers move and shift over time. Using dynamic models, we highlight that safety is an emergent property of a system, where small errors accumulate and can lead to larger, more significant failures. We also examine the role of human error, risk management, and attention to detail in preventing accidents and emphasize the complexity of real-world systems, where multiple factors often lead to a critical mass of failure before an incident happens.
Original blog: https://www.thehumandiver.com/blog/when-the-holes-line-up
Links: Animated simple Swiss Cheese model: https://vimeo.com/326723142
Big Hole model: https://vimeo.com/326723122
Little Hole model: https://vimeo.com/326723109
Tags: English, Gareth Lock, Human Factors, Incident Investigation