

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

Dec 27, 2025 • 8min
SH239: Top Tips for Beginner Divers: Teamwork
In this episode, we look at how two new divers learned the hard way that being a true buddy team takes more than just diving side by side. A simple dive on a house reef became stressful when assumptions replaced communication, and neither diver had agreed on roles, pace, or what to do if something went wrong. Their experience shows that teamwork doesn’t happen automatically—it’s built through clear plans, shared expectations, and honest conversations before and after the dive. We explore how new divers can avoid “assumed coordination,” develop a shared mental model, and grow stronger as a team using practical tools like pre-dive role discussions, simple communication habits, quick debriefs, and psychological safety. Effective teamwork helps divers stay connected, learn together, and enjoy safer, more relaxed dives.
Original blog: https://www.thehumandiver.com/blog/top-tips-for-beginner-divers-teamwork
Links: Debrief model: https://www.thehumandiver.com/blog/debriefing
Building psychological safety: https://www.thehumandiver.com/blog/the-challenge-of-psychological-safety
Tags: English, Beginners, Brief, Debrief, Gareth Lock, Teamwork

Dec 24, 2025 • 7min
SH238: Top tips for Beginner Divers: Communications
In this episode, we look at how a simple miscommunication during a fun dive turned into confusion, and why clear planning and shared understanding are essential for safe and enjoyable diving. Because you can’t talk underwater, communication has to start at the surface, and most problems come from assumptions, unclear plans, or people being too nervous to speak up. We break down practical tools to avoid this—like agreeing on the dive plan, using shared hand signals, confirming understanding, carrying a slate, and doing short debriefs after each dive. Good communication builds confidence, strengthens teamwork, and prevents small misunderstandings from turning into big issues.
Original blog: https://www.thehumandiver.com/blog/top-tips-for-beginner-divers-communication
Links: Shared understanding: https://www.thehumandiver.com/blog/lost-in-translation
Blog about psychological safety: https://www.thehumandiver.com/blog/the-challenge-of-psychological-safety
Ask questions: https://www.thehumandiver.com/blog/communications-ask-better-questions
Tags: English, Briefing, Communication, Communications, Mike Mason, Teamwork

Dec 20, 2025 • 5min
SH237: Decision Making: Normalisation of Deviance in Rebreather Cave Diving
In this episode, we explore how easy it is for divers to drift into unsafe habits when risky behaviour seems to have no consequences, especially in small or high-performing cave and technical diving teams. A real example from a cave rebreather class shows how a simple shortcut- only a few metres and seemingly low-risk- could have broken a key rule of always maintaining a continuous guideline. Even when a team is skilled and conditions look perfect, small deviations can become normalised and lead to bigger risks later. We talk about why psychological safety, honest communication, and clear team standards are essential for spotting drift, challenging unsafe ideas, and learning from each other.
Original blog: https://www.thehumandiver.com/blog/top-tips-blog-normalisation-of-deviance-in-rebreather-cave-diving
Links: Normalisation of deviance: https://www.thehumandiver.com/blog/normalisation-of-deviance-not-about-rule-breaking
Psychological safety: https://www.thehumandiver.com/blog/what-we-get-wrong-about-psychological-safety-in-diving
Tags: English, Cave Diving, CCR, Decision Making, Lanny Vogel, Normalisation of Deviance, Teamwork

Dec 17, 2025 • 8min
SH236: Reframing The Dirty Dozen - Part 4
In this episode, we finish exploring the “Dirty Dozen” human factors that contribute to mistakes in diving by looking at fatigue, lack of assertiveness and norms. These factors influence how divers think and behave, and they can increase risk if they aren’t recognised and managed. Fatigue can reduce focus and reaction time, lack of assertiveness can stop people from speaking up when something feels wrong, and unsafe norms can develop when teams skip important steps simply because “nothing went wrong last time.” We discuss how to address these issues through tools like HALT and PACE, building psychological safety, supporting each other as teammates, and challenging negative habits within dive communities. The goal is to create an environment where divers can speak up, look out for each other and make safer decisions together.
Original blog: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-4
Links: Part One: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-1
Part Two: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-2
Part Three: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-3
Error Producing Conditions: https://www.thehumandiver.com/blog/hf-for-dummies-part-9-error-producing-conditions
Building psychological safety: https://www.thehumandiver.com/blog/team-building-psych-safety-1
PACE tool: https://www.thehumandiver.com/blog/navigating-the-authority-gradient-pt2
Negative norms need to be recognised: https://www.thehumandiver.com/blog/what-are-we-pretending-not-to-know
Normalisation of drift vs pushing boundaries: https://www.thehumandiver.com/blog/drift-vs-advancement-how-do-we-push-limits-safely
Tags: English, Fatigue, Human Error, Jenny Lord, Performance Shaping Factors

Dec 13, 2025 • 7min
SH235: Reframing The Dirty Dozen - Part 3
In this episode, we continue exploring the “Dirty Dozen,” a set of human factors that can lead to mistakes in diving, by looking at pressure, lack of awareness, and lack of knowledge. These factors affect divers of all levels because they shape how we think, act, and make decisions underwater. Pressure—whether from time, money, or other people—can push divers into taking risks or rushing, while lack of awareness can cause them to miss important changes in their surroundings. Lack of knowledge, including not knowing what you don’t know, can lead to poor decisions or unsafe actions, especially in new environments or with unfamiliar equipment. We also discuss practical ways to manage these issues, such as improving skills so tasks become automatic, sharing responsibilities within the team, building a supportive culture, asking open questions, and staying curious about the “why” behind procedures.
Original blog: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-3
Links: Part One: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-1
Part Two: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-2
Part Four: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-4
Tags: English, Communication, Fatigue, Jenny Lord, Performance Shaping Factors, Situation Awareness, Stress

Dec 10, 2025 • 9min
SH234: Reframing The Dirty Dozen - Part 2
In Part 2 of this blog, we delve into three more of the "Dirty Dozen" human factors—stress, complacency, and lack of teamwork—and explore their impact on diver performance and safety. Stress, whether acute or chronic, can reduce awareness and decision-making ability, while complacency often arises in routine tasks, lowering vigilance. A lack of teamwork, meanwhile, undermines coordination and increases risks during emergencies. Practical countermeasures like using checklists, fostering psychological safety, and setting clear team goals can help mitigate these issues, creating safer and more effective dive environments.
Original blog: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-2
Links: HALT Model: https://www.thehumandiver.com/blog/stress-a-challenge-we-all-face
Becoming a team: https://www.thehumandiver.com/blog/practical-application-of-teamwork-in-diver-training
Building Psychological Safety blog series: https://www.thehumandiver.com/blog/team-building-psych-safety-1
UNITED-C: https://www.thehumandiver.com/blog/Why%20are%20dive%20briefings%20important%3F%20How%20to%20deliver%20them%20effectively
Part 1: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-1
Part 3: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-3
Part 4: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-4
Tags: English, Gareth Lock, Human Error, Human Factors, Jenny Lord, Teamwork

Dec 6, 2025 • 10min
SH233: Reframing The Dirty Dozen - Part 1
This week’s episode explores the interplay between human factors and system design in diving safety, using the “Dirty Dozen” as a framework to highlight key risks like poor communication, distraction, and lack of resources. While this list simplifies complex issues, it underscores how systemic challenges and individual behaviors intersect to create safety risks. The episode dives into practical countermeasures, emphasizing the need for teamwork, thorough preparation, and robust support systems to mitigate errors. By unpacking the context behind the Dirty Dozen, we aim to help divers and teams enhance safety, improve operations, and foster a culture of accountability and resilience.
Original blog: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-1
Links: LinkedIn Post from Gareth Lock: https://www.linkedin.com/posts/garethlock_mca-dirty-dozen-graphic-activity-7328740642400931840-tzS4/?utm_source=share&utm_medium=member_ios&rcm=ACoAAAELqPcBwf1_VKIPpplosn5XZ02d6xlOzRs
HFiD Applied Skills classes: https://www.thehumandiver.com/hfid-training-2025
Our brains process words faster than we can transmit or receive them
Checklists blog: https://www.thehumandiver.com/blog/designing-checklists-that-work-slowing-down-to-get-it-right
Normalisation of Deviance blog: https://www.thehumandiver.com/blog/normalisation-of-deviance-not-about-rule-breaking
Part 2: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-2
Part 3: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-3
Part 4: https://www.thehumandiver.com/blog/reframing-the-dirty-dozen-part-4
Tags: English, Communication, Gareth Lock, Human Error, Human Factors, Jenny Lord

Dec 3, 2025 • 8min
SH232: Instructor Toxicity: Why one bad apple really does spoil the bunch
This blog by Pedro Paulo Cunha explores the critical role of leadership in dive safety, highlighting how a toxic leader at a dive resort created a culture of fear, harassment, and stress that compromised both staff well-being and guest safety. Through the story of an experienced instructor facing verbal abuse and misconduct, the piece underscores the importance of psychological safety, just culture, and accountability in high-risk environments. It reveals how poor leadership eroded team confidence, increased errors, and damaged the operation’s reputation, offering valuable lessons for divers and managers alike. Leadership isn’t about rank but about fostering trust, communication, and resilience—qualities essential for safer and more effective dive operations.
Original blog: https://www.thehumandiver.com/blog/instructor-toxicity-why-one-bad-apple-spoils-the-bunch
Tags: English, Just Culture, Leadership, Pedro Paulo Cunha, Psychological Safety, Teamwork

Nov 29, 2025 • 9min
SH231: What do you mean, the damn box is missing again?
Andrzej Gornicki reflects on the challenges of teamwork and organisation in diving operations, sharing lessons from his experience running a dive centre. Through real-life stories, he highlights how logistical oversights and errors—like forgotten equipment or missing supplies—can be mitigated with clear protocols and checklists. However, simply having checklists isn’t enough; they need to be embraced by the team. By involving staff in creating their own task-specific checklists and placing them strategically, Andrzej fostered accountability and improved efficiency. This episode dives into the balance between organisation, teamwork, and experience, showing how small changes can make big differences in safety and performance.
Original blog: https://www.thehumandiver.com/blog/what-do-you-mean-the-damn-box-is-missing-again
Links: Introducing checklists in diving: https://www.thehumandiver.com/blog/risk-management-in-diving
Amazon link ‘The Checklist Manifesto: How to Get Things Right’
Tags: English, Andrzej Górnicki, Checklists, Leadership, Teamwork

Nov 26, 2025 • 10min
SH230: What We Get Wrong About Psychological Safety in Diving
Psychological safety is more than a buzzword—it's a critical team skill in high-risk environments like diving. Often misunderstood, it's not about being nice or avoiding discomfort, but about fostering an environment where team members feel safe to speak up, question, and learn without fear of judgment. Through real-life examples, including a gas switch error during a dive, this episode explores the transformative power of psychological safety in improving communication, accountability, and team performance. Dive into how candid conversations, challenging feedback, and a culture of learning can make dive teams safer and stronger.
Original blog: https://www.thehumandiver.com/blog/what-we-get-wrong-about-psychological-safety-in-diving
Links: If Ony… documentary: https://www.thehumandiver.com/ifonly
YouTube presentation on the Linnea Mills
Blogs about PS from the Human Diver
Outcomes are a function of technical skills, context, skill/luck, and non-technical skills Youtube video
This article was written based on an HBR article by Professor Amy Edmondson & Michaela Kerrissey, "What People Get Wrong About Psychological Safety" (Harvard Business Review, May–June 2025)
Tags: English, Gareth Lock, Leadership, Psychological Safety, Teamwork


