Community
RF4 Consensus Statements
One of the deliverables of Rebreather Forum 4 was a set of “consensus statements” that reflected the views of participants on issues deemed important to the Forum. The statements, published here, were crafted by Drs. Simon Mitchell and Neal Pollock based on the presentations and discussed and voted by delegates through a democratic process. The statements will be included in the RF4 Proceedings along with an edited version of the discussions surrounding each statement
by Drs. Simon J. Mitchell and Neal W. Pollock. Images by Jason Brown, BARDOPhotographic unless noted.

Following the precedent set in Rebreather Forum 3 the final half day of the 2023 meeting was dedicated to discussion of a series of consensus statements intended to reflect widely supported opinions of participants. The statements were drafted by the authors during the course of the meeting, and were explicitly designed to be confluent with important messages emerging from presentations and any subsequent discussion. The statements do not purport to be the only important messages to emerge from the forum; the authors focused on matters that seemed important, widely supported and relatively non-controversial, and that would therefore lend themselves to meaningful consensus.
The statements were presented one by one to a plenary session of participants and discussion was invited. The amount of discussion was variable with some statements attracting little, and others requiring more debate and wordsmithing which was performed live. As is the case with sessions of this nature some degree of directive chairmanship was required in order to work through the list of statements within the allocated time. For this reason discussion of some statements had to be truncated but there was substantial discussion of all statements that emerged as controversial for any reason. For transparency, a transcript of the discussion will be presented in the forum proceedings (edited to correct grammar and eliminate extraneous comments, but retaining the spirit and intent of the original dialogue). At the end of discussion of each statement a show of hands was taken to gauge agreement and disagreement with the statement. It was announced prospectively that a clear majority of participants would need to agree for a statement to make the published list. Ultimately, after discussion and rewording where necessary all draft statements were accepted; most unanimously and never with more than 5-10% in disagreement.
The 28 statements are presented in thematic areas designated “safety,” “research,” “operational issues,” “education and training,” and “engineering.” The authors acknowledge that some of these statements seem relevant to multiple themes. Most are self-explanatory, but some are accompanied by contextualizing narrative from the authors where necessary.

Thematic Area “Safety”
Accident Data
Analysis of contemporary rebreather accident data indicates a continued need for integrated effort to reduce the rates of injury, morbidity, and mortality associated with rebreather diving.
Cardiac Health Surveillance
The forum endorses the principle of periodic cardiac health surveillance for all rebreather divers with an emphasis on targeted annual or biennial evaluation for divers older than 45 years even in apparent good health.
Contextualizing narrative: the forum resolved that this statement should be accompanied by citation of relevant supportive medical literature. Various studies have identified the importance of cardiac events as the disabling injury in recreational diving fatalities,2,3 and an expert consensus guideline for cardiac evaluation of divers was recently published.4
Accident Analysis
The analysis of accident, incident, and injury data from rebreather incidents should consider wider contextual elements and error-producing conditions and not just immediate contributory factors.
Solo Diving
The forum recognizes that solo diving may increase the likelihood of a fatality in the event of a rebreather diving incident.
Pre-Entry Checklists
The forum strongly advocates the use of a pre-entry checklist (in a check and response format if practicable) administered just prior to water entry. This should be a brief checklist addressing contextually relevant critical safety items such as “rebreather switched on,” “oxygen cylinder on,” “diluent cylinder on,” “wing/buoyancy device/drysuit inflation connected and working.”

Thematic Area “Research”
Training and Sales Data
The forum strongly endorses continued collection of anonymized rebreather diver training and rebreather unit sales data by the Divers Alert Network Research Department as an adjunct to interpreting diver accident statistics.
Mishap and Near-Miss Reporting
The forum advocates self-reporting of diving mishaps and near-misses, and reporting of fatalities, to the DAN diving incident reporting system.
Contextualizing narrative: The DAN diving incident reporting system was nominated in this statement because of its high visibility, global scope, and accessibility for divers anywhere in the world. However, the forum also acknowledged the value of national or regional systems of relevant data collection and analysis (such as that run by the British Sub-Aqua Club [BSAC]) and also advocates for maintenance of diver reporting to such systems. Data sharing between DAN and regional groups was also discussed and was supported.
End-Tidal CO2 Monitoring
The forum identifies as a research priority/goal the development of capnography and accurate end-tidal CO2 monitoring for rebreathers.
Regenerating CO2 Absorption Technology
The forum identifies as a research priority the development of regenerating CO2 absorption technologies.
Full-Face Masks
In relation to a documented RF3 research priority, the forum recognizes the emergence of data pertaining to the efficacy of full-face masks in preventing water aspiration in unconscious subjects.5 This strengthens the argument for considering their use in scenarios associated with an elevated risk of oxygen toxicity such as in-water recompression.
Real-Time Physiological Monitoring
The forum endorses ongoing research into strategies for real-time diver physiological monitoring.

Thematic Area “Operational Issues”
Bailout Rebreathers
The forum identifies as a priority/goal the development and documentation of practices and/or monitoring for optimizing bailout rebreather use.
Mouthpiece Retaining Straps
The forum recognizes the use of correctly deployed mouthpiece retaining straps as a strategy for avoiding loss of the mouthpiece and minimization of water aspiration in the event of loss of consciousness underwater.
Bailout Valves
The forum recognizes the potential advantage of a bailout valve for transitioning from closed- to open-circuit in the event of hypercapnia or other events requiring bailout; this advantage requires a high performance open-circuit breathing system.
Mixed Mode Diving
The forum recognizes mixed mode diving as a legitimate buddy option in dives of appropriate scope but recommends a mixed mode briefing, and pre-establishment of strategies for gas sharing.
Contextualizing narrative: ‘Mixed mode’ in this context refers to divers using different underwater breathing apparatus types working as a buddy pair, for example, and open-circuit diver diving with a rebreather diver.
Mixed Platform Diving
The forum recognizes mixed platform diving as a legitimate buddy option and recommends at least a mixed platform briefing with emphasis on emergency procedures.
Contextualizing narrative: ‘Mixed platform’ in this context refers to divers using different brands or models of the same underwater breathing apparatus type working as a buddy pair, for example, two divers using different brands of rebreather.
Asymmetric Equipment
The forum recognizes symmetric (same rebreather unit) or asymmetric (different rebreather unit) multiple rebreather systems as options for an alternative breathing or bailout system.
Contextualizing narrative: ‘Symmetric’ in this context refers to multiple rebreathers of the same make and type, and ‘asymmetric’ refers to multiple rebreathers of different makes or types.
Head-up Display
The forum recommends the display of safety-critical information such as loop oxygen status on a head-up display.
Standard Operating Procedures and Emergency Action Plan Documentation
The forum endorses the compilation of a contextually tailored and detailed dive plan/standard operating procedures document and emergency action plan prior to rebreather diving expeditions.
Emergency Preparedness
The forum endorses the importance of emergency preparedness including a validated emergency action plan, oxygen supplies, access to appropriate medical support with adequate medical supplies, and evacuation plans during rebreather diving expeditions; particularly to remote locations.
In-Water Recompression
The forum recognizes the recent medical endorsement of emergency in-water recompression of selected divers by appropriately equipped teams trained in oxygen decompression.6,7

Thematic Area “Education and Training”
Manufacturer-Training Agency Coordination
The forum recognizes the challenges for training agencies in maintaining confluence between course content/availability and emergence of new rebreather technologies. The forum endorses close liaison between training agencies and manufacturers (including factory trainers) to share information about emerging technologies and manufacturer expectations on training approaches using their platforms.
Knowledge Gap Targets
The forum identifies the following as common knowledge gaps that constitute educational opportunities for rebreather instructors and leaders to address:
- Predispositions, symptoms, and frequency of immersion pulmonary edema
- Increasing risk of deeper dives executed perfectly on the same decompression algorithm (ie, not iso-risk exposures)
- Scope of variability in venous gas emboli counts in individual divers serially performing identical dives and the associated implications for interpretation of individual monitoring of venous gas emboli post-dive
- The difference between CO2 inhalation and hypoventilation as the two mechanisms of hypercapnia in rebreather diving.
- Correct management of ingestion/inhalation of caustic scrubber byproduct (ie, ‘caustic cocktail’)
- Function of CO2 scrubbers
Contextualizing narrative: It is emphasized that this list is not intended to define all relevant knowledge gaps. Rather, it contains items that emerged as obvious educational opportunities in the various presentations and discussion at Rebreather Forum 4.
Diver Retraining/Updating
The forum recognizes the potential for skill and knowledge degradation over time or during periods of diving inactivity and encourages training agency initiatives to promote continuing education and training, refresher options, and/or recertification as appropriate.

Thematic Area “Engineering”
Oxygen Sensor Replacement Warning
The forum recommends that manufacturer’s consider incorporating oxygen sensor replacement warnings in rebreather operating systems
Contextualizing narrative: The context in which this discussion took place was that these warnings would be based on elapsed time since sensor manufacture.
Gas Density Display
The forum recommends that rebreather manufacturers consider incorporating gas density displays and/or alarms in the user interface.
Contextualizing narrative: The discussion around this statement included strong advocacy for viewing gas density as a dive planning and operational concern that requires careful consideration.
Orientation Monitoring
The forum identifies optimally positioned accelerometers or inclinometers with rebreathers as an opportunity for capturing diver trim and movement data that could be used for training, performance, and forensic evaluation.
Inspired CO2 Monitoring
The forum recognizes the potential safety advantage of inhale side CO2 or scrubber monitors, but acknowledges that they may fail to detect some causes of hypercapnia.
References
- Mitchell SJ. Rebreather Forum 3 consensus. In: Vann RD, Denoble PJ, Pollock NW, eds. Rebreather Forum 3 Proceedings. Durham NC: AAUS/DAN/PADI;2014. p. 287–302.
- Lippmann J, Taylor DM. Scuba diving fatalities in Australia 2001 to 2013: chain of events. Diving Hyperb Med. 2020;50(3):220–229.
- Denoble PJ, Caruso JL, Dear Gd, Pieper CF, Vann RD. Common causes of open-circuit recreational diving fatalities. Undersea Hyperb Med. 2008; 35(6):393–406.
- Jepson N, Rienks R, Smart D, Bennett MH, Mitchell SJ, Turner M. South Pacific Underwater Medicine Society guidelines for cardiovascular risk assessment of divers. Diving Hyperb Med. 2020;50(3):273–277.
- van Waart H, Harris RJ, Gant N, Vrijdag XCE, Challen CJ, Lawthaweesawat C, Mitchell SJ. Deep anaesthesia: the Thailand cave rescue and its implications for management of the unconscious diver underwater. Diving Hyperb Med. 2020;50(2):121–129.
- Mitchell SJ, Bennett MH, Bryson P, Butler FK, Doolette DJ, Holm JR, Kot J, Lafere P. Pre-hospital management of decompression illness: expert review of key principles and controversies. Diving Hyperb Med. 2018;48(1):45–55.
- Doolette DJ, Mitchell SJ. In-water recompression. Diving Hyperb Med. 2018;48(2):84–95.
DIVE DEEPER
Rebreather Forum 3.0 Consensus Statements (2012)
Rebreather Forum 2.0 Findings & Recommendations (1996)

Simon Mitchell, MB ChB, PhD, FANZCA Simon works as an anaesthesiologist and diving physician, and is Professor of Anaesthesiology at the University of Auckland. He is widely published in diving medicine and physiology. Simon has a long career in sport, scientific, commercial, and military diving. He is an active technical diver and was first to dive and identify three historically significant deep shipwrecks in Australia and New Zealand, including one in 2002 which was the deepest wreck dive undertaken at the time. He was conferred Fellowship of the Explorers’ Club of New York in 2006, and was the DAN Rolex Diver of the Year in 2015.

Neal W. Pollock, PhD Neal Pollock holds a Research Chair in Hyperbaric and Diving Medicine and is an Associate Professor in Kinesiology at Université Laval in Québec, Canada. He was previously Research Director at Divers Alert Network (DAN) in Durham, North Carolina. His academic training is in zoology, exercise physiology and environmental physiology. His research interests focus on human health and safety in extreme environments. He is an emeritus editor-in-chief of the journal Wilderness & Environmental Medicine. He began open-circuit diving in 1979, and closed-circuit diving in 2002.
Community
Twenty-five Years in the Pursuit of Excellence – The Evolution and Future of GUE
Founder and president Jarrod Jablonski describes his more than a quarter of a century long quest to promote excellence in technical diving.

by Jarrod Jablonski. Images courtesy of J. Jablonski and GUE unless noted.
The most difficult challenges we confront in our lives are the most formative and are instrumental in shaping the person we become. When I founded Global Underwater Explorers (GUE), the younger version of myself could not have foreseen all the challenges I would face, but equally true is that he would not have known the joy, the cherished relationships, the sense of purpose, the rich adventures, the humbling expressions of appreciation from those impacted, or the satisfaction of seeing the organization evolve and reshape our industry. Many kindred souls and extraordinary events have shaped these last 25 years, and an annotated chronology of GUE is included in this issue of InDEPTH. This timeline, however, will fail to capture the heart behind the creation of GUE, it will miss the passionate determination currently directing GUE, or the committed dedication ready to guide the next 25 years.

I don’t remember a time that I was not in, around, and under the water. Having learned to swim before I could walk, my mother helped infuse a deep connection to the aquatic world. I was scuba certified in South Florida with my father, and promptly took all our gear to North Florida where I became a dive instructor at the University of Florida. It was then that I began my infatuation with cave diving. I was in the perfect place for it, and my insatiable curiosity was multiplied while exploring new environments. I found myself with a strong desire to visit unique and hard-to-reach places, be they far inside a cave or deep within the ocean.
My enthusiasm for learning was pressed into service as an educator, and I became enamored with sharing these special environments. Along with this desire to share the beauty and uniqueness of underwater caves was a focused wish to assist people in acquiring the skills I could see they needed to support their personal diving goals. It could be said that these early experiences were the seeds that would germinate, grow, mature, and bloom into the organizing principles for GUE.



The Pre-GUE Years
Before jumping into the formational days of GUE, allow me to help you visualize the environment that was the incubator for the idea that became GUE’s reality. By the mid-1990s, I was deeply involved in a variety of exploration activities and had been striving to refine my own teaching capacity alongside this growing obsession for exploratory diving. While teaching my open water students, I was in the habit of practicing to refine my own trim and buoyancy, noticing that the students quickly progressed and were mostly able to copy my position in the water. Rather than jump immediately into the skills that were prescribed, I started to take more time to refine their comfort and general competency. This subtle shift made a world of difference in the training outcomes, creating impressive divers with only slightly more time and a shift in focus. In fact, the local dive boats would often stare in disbelief when told these divers were freshly certified, saying they looked better than most open water instructors!
By this point in my career, I could see the problems I was confronting were more systemic and less individualistic. In retrospect, it seemed obvious that key principles had been missing in both my recreational and technical education, not to mention the instructor training I received. The lack of basic skill refinement seemed to occur at all levels of training, from the beginner to the advanced diver. Core skills like buoyancy or in-water control were mainly left for divers to figure out on their own and almost nobody had a meaningful emphasis on efficient movement in the water. It was nearly unheard of to fail people in scuba diving, and even delaying certification for people with weak skills was very unusual. This remains all too common to this day, but I believe GUE has shifted the focus in important ways, encouraging people to think of certification more as a process and less as a right granted to them because they paid for training.

The weakness in skill refinement during dive training was further amplified by little-to-no training in how to handle problems when they developed while diving, as they always do. In those days, even technical/cave training had very little in the way of realistic training in problem resolution. The rare practice of failures was deeply disconnected from reality. For example, there was almost no realistic scenario training for things like a failed regulator or light. What little practice there was wasn’t integrated into the actual dive and seemed largely useless in preparing for real problems. I began testing some of my students with mock equipment failures, and I was shocked at how poorly even the best students performed. They were able to quickly develop the needed skills, but seeing how badly most handled their first attempts left me troubled about the response of most certified divers should they experience problems while diving, as they inevitably would.
Diving Fatalities
Meanwhile, I was surrounded by a continual progression of diving fatalities, and most appeared entirely preventable. The loss of dear friends and close associates had a deep impact on my view of dive training and especially on the procedures being emphasized at that time within the community. The industry, in those early days, was wholly focused on deep air and solo diving. However, alarmingly lacking were clear bottle marking or gas switching protocols. It seemed to me to be no coincidence that diver after diver lost their lives simply because they breathed the wrong bottle at depth. Many others died mysteriously during solo dives or while deep diving with air.
One of the more impactful fatalities was Bob McGuire, who was a drill sergeant, friend, and occasional dive buddy. He was normally very careful and focused. One day a small problem with one regulator caused him to switch regulators before getting in the water. He was using a system that used color-coded regulators to identify the gas breathed. When switching the broken regulator, he either did not remember or did not have an appropriately colored regulator. This small mistake cost him his life. I clearly remember turning that one around in my head quite a bit. Something that trivial should not result in the loss of a life.
Also disturbing was the double fatality of good friends, Chris and Chrissy Rouse, who lost their lives while diving a German U-boat in 70 m/230 ft of water off the coast of New Jersey. I remember, as if the conversation with Chris were yesterday, asking him not to use air and even offering to support the cost as a counter to his argument about the cost of helium. And the tragedies continued: The loss of one of my closest friends Sherwood Schille, the death of my friend Steve Berman who lived next to me and with whom I had dived hundreds of times, the shock of losing pioneering explorer Sheck Exley, the regular stream of tech divers, and the half dozen body recoveries I made over only a couple years, which not only saddened me greatly, but also made me angry. Clearly, a radically different approach was needed.
Learning to Explore
Meanwhile, my own exploration activities were expanding rapidly. Our teams were seeking every opportunity to grow their capability while reducing unnecessary risk. To that end, we ceased deep air diving and instituted a series of common protocols with standardized equipment configurations, both of which showed great promise in expanding safety, efficiency, and comfort. We got a lot of things wrong and experienced enough near misses to keep us sharp and in search of continual improvement.

But we looked carefully at every aspect of our diving, seeking ways to advance safety, efficiency, and all-around competency while focusing plenty of attention into the uncommon practice of large-scale, team diving, utilizing setup dives, safety divers, and inwater support. We developed diver propulsion vehicle (DPV) towing techniques, which is something that had not been done previously. We mostly ignored and then rewrote CNS oxygen toxicity calculations, developed novel strategies for calculating decompression time, and created and refined standard procedures for everything from bottle switching to equipment configurations. Many of these developments arose from simple necessity. There were no available decompression programs and no decompression tables available for the dives we were doing. Commonly used calculations designed to reduce the risk of oxygen toxicity were useless to our teams, because even our more casual dives were 10, 20, or even 30 times the allowable limit. The industry today takes most of this for granted, but in the early days of technical diving, we had very few tools, save a deep motivation to go where no one had gone before.

Many of these adventures included friends in the Woodville Karst Plain Project (WKPP), where I refined policies within the team and most directly with longtime dive buddy George Irvine. This “Doing it Right” (DIR) approach sought to create a more expansive system than Hogarthian diving, which itself had been born in the early years of the WKPP and was named after William Hogarth Main, a friend and frequent dive buddy of the time. By this point, I had been writing about and expanding upon Hogarthian diving for many years. More and more of the ideas we wanted to develop were not Bill Main’s priorities and lumping them into his namesake became impractical, especially given all the debate within the community over what was and was not Hogarthian.
A similar move from DIR occurred some years later when GUE stepped away from the circular debates that sought to explain DIR and embraced a GUE configuration with standard protocols, something entirely within our scope to define.
These accumulating events reached critical mass in 1998. I had experienced strong resistance to any form of standardization, even having been asked to join a special meeting of the board of directors (BOD) for a prominent cave diving agency. Their intention was to discourage me from using any form of standard configuration, claiming that students should be allowed to do whatever they “felt’ was best. It was disconcerting for me, as a young instructor, to be challenged by pioneers in the sport; nevertheless, I couldn’t agree with the edict that someone who was doing something for the first time should be tasked with determining how it should be done.
This sort of discussion was common, but the final straw occurred when I was approached by the head of a technical diving agency, an organization for which I had taught for many years. I was informed that he considered it a violation of standards not to teach air to a depth of at least 57 m/190 ft. This same individual told me that I had to stop using MOD bottle markings and fall in line with the other practices endorsed by his agency. Push had finally come to shove, and I set out to legitimize the training methods and dive protocols that had been incubating in my mind and refined with our teams over the previous decade. Years of trial and many errors while operating in dynamic and challenging environments were helping us to identify what practices were most successful in support of excellence, safety, and enjoyment.
Forming GUE
Forming GUE as a non-profit company was intended to neutralize the profit motivations that appeared to plague other agencies. We hoped to remove the incentive to train—and certify—the greatest number of divers as quickly as possible because it seemed at odds with ensuring comfortable and capable divers. The absence of a profit motive complemented the aspirational plans that longtime friend Todd Kincaid and I had dreamed of. We imagined a global organization that would facilitate the efforts of underwater explorers while supporting scientific research and conservation initiatives.
I hoped to create an agency that placed most of the revenue in the hands of fully engaged and enthusiastic instructors, allowing them the chance to earn a good living and become professionals who might stay within the industry over many years. Of course, that required forgoing the personal benefit of ownership and reduced the revenue available to the agency, braking its growth and complicating expansion plans. This not only slowed growth but provided huge challenges in developing a proper support network while creating the agency I envisioned. There were years of stressful days and nights because of the need to forgo compensation and the deep dependance upon generous volunteers who had to fit GUE into their busy lives. If it were not for these individuals and our loyal members, we would likely never have been successful. Volunteer support and GUE membership have been and remain critical to the growing success of our agency. If you are now or have ever been a volunteer or GUE member, your contribution is a significant part of our success, and we thank you.

The challenges of the early years gave way to steady progress—always slower than desired, with ups and downs, but progress, nonetheless. Some challenges were not obvious at the outset. For example, many regions around the world were very poorly developed in technical diving. Agencies intent on growth seemed to ignore that problem, choosing whoever was available, and regardless of their experience in the discipline, they would soon be teaching.
This decision to promote people with limited experience became especially problematic when it came to Instructor Trainers. People with almost no experience in something like trimix diving were qualifying trimix instructors. Watching this play out in agency after agency, and on continent after continent, was a troubling affair. Conversely, it took many years for GUE to develop and train people of appropriate experience, especially when looking to critical roles, including high-level tech and instructor trainers. At the same time, GUE’s efforts shaped the industry in no small fashion as agencies began to model their programs after GUE’s training protocols. Initially, having insisted that nobody would take something like Fundamentals, every agency followed suit in developing their own version of these programs, usually taught by divers that had followed GUE training.
This evolving trend wasn’t without complexity but was largely a positive outcome. Agencies soon focused on fundamental skills, incorporated some form of problem-resolution training, adhered to GUE bottle and gas switching protocols, reduced insistence on deep air, and started talking more about developing skilled divers, among other changes. This evolution was significant when compared to the days of arguing about why a person could not learn to use trimix until they were good while diving deep on air.
To be sure, a good share of these changes was more about maintaining business relevance than making substantive improvements. The changes themselves were often more style than substance, lacking objective performance standards and the appropriate retraining of instructors. Despite these weaknesses, they remain positive developments. Talking about something is an important first step and, in all cases, it makes room for strong instructors in any given agency to practice what is being preached. In fact, these evolving trends have allowed GUE to now push further in the effort to create skilled and experienced divers, enhancing our ability to run progressively more elaborate projects with increasingly more sophisticated outcomes.
The Future of GUE
The coming decades of GUE’s future appear very bright. Slow but steady growth has now placed the organization in a position to make wise investments, ensuring a vibrant and integrated approach. Meanwhile, evolving technology and a broad global base place GUE in a unique and formidable position. Key structural and personnel adjustments complement a growing range of virtual tools, enabling our diverse communities and representatives to collaborate and advance projects in a way that, prior to now, was not possible. Strong local communities can be easily connected with coordinated global missions; these activities include ever-more- sophisticated underwater initiatives as well as structural changes within the GUE ecosystem. One such forward-thinking project leverages AI-enabled, adaptive learning platforms to enhance both the quality and efficiency of GUE education. Most agencies, including GUE, have been using some form of online training for years, but GUE is taking big steps to reinvent the quality and efficiency of this form of training. This is not to replace, but rather to extend and augment inwater and in-person learning outcomes. Related tools further improve the fluidity, allowing GUE to seamlessly connect previously distant communities, enabling technology, training, and passion to notably expand our ability to realize our broad, global mission.

Meanwhile, GUE and its range of global communities are utilizing evolving technologies to significantly expand the quality and scope of their project initiatives. Comparing the impressive capability of current GUE communities with those of our early years shows a radical and important shift, allowing results equal or even well beyond those possible when compared even with well-funded commercial projects. Coupled with GUE training and procedural support, these ongoing augmentations place our communities at the forefront of underwater research and conservation. This situation will only expand and be further enriched with the use of evolving technology and closely linked communities. Recent and planned expansions to our training programs present a host of important tools that will continue being refined in the years to come. Efforts to expand and improve upon the support provided to GUE projects with technology, people, and resources are now coming online and will undoubtedly be an important part of our evolving future.
The coming decades will undoubtedly present challenges. But I have no doubt that together we will not only overcome those obstacles but we will continue to thrive. I believe that GUE’s trajectory remains overwhelmingly positive, for we are an organization that is continually evolving—driven by a spirit of adventure, encouraged by your heartwarming stories, and inspired by the satisfaction of overcoming complex problems. Twenty-five years ago, when I took the path less traveled, the vision I had for GUE was admittedly ambitious. The reality, however, has exceeded anything I could have imagined. I know that GUE will never reach a point when it is complete but that it will be an exciting lifelong journey, one that, for me, will define a life well lived. I look forward our mutual ongoing “Quest for Excellence.”
See Listings Below For Additional Resources On GUE And GUE Diving!

Jarrod is an avid explorer, researcher, author, and instructor who teaches and dives in oceans and caves around the world. Trained as a geologist, Jarrod is the founder and president of GUE and CEO of Halcyon and Extreme Exposure while remaining active in conservation, exploration, and filming projects worldwide. His explorations regularly place him in the most remote locations in the world, including numerous world record cave dives with total immersions near 30 hours. Jarrod is also an author with dozens of publications, including three books.
A Few GUE Fundamentals
Similar to military, commercial and public safety divers, Global Underwater Explorers (GUE) is a standards-based diving community, with specific protocols, standard operating procedures (SOPs) and tools. Here are selected InDEPTH stories on some of the key aspects of GUE diving, including a four-part series on the history and development of GUE decompression procedures by founder and president Jarod Jablonski.

Anatomy of a Fundamentals Class
GUE Instructor Examiner Guy Shockey explains the thought and details that goes into GUE’s most popular course, Fundamentals, aka “Fundies,” which has been taken by numerous industry luminaries. Why all the fanfare? Shockey characterizes the magic as “simple things done precisely!

Back to Fundamentals: An Introduction to GUE’s Most Popular Diving Course
Instructor evaluator Rich Walker attempts to answer the question, “why is Fundamentals GUE’s most popular diving course?” Along the way, he clarifies some of the myths and misconceptions about GUE training. Hint: there is no Kool-Aid.

As you’d expect, Global Underwater Explorers (GUE) has a standardized approach to prepare your equipment for the dive, and its own pre-dive checklist: the GUE EDGE. Here explorer and filmmaker Dimitris Fifis preps you to take the plunge, GUE-style.

The Flexibility of Standard Operating Procedures
Instructor trainer Guy Shockey discusses the purpose, value, and yes, flexibility of standard operating procedures, or SOPs, in diving. Sound like an oxymoron? Shockey explains how SOPs can help offload some of our internal processing and situational awareness, so we can focus on the important part of the dive—having FUN!

Standard Gases: The Simplicity of Everyone Singing the Same Song
Like the military and commercial diving communities before them, Global Underwater Explorers (GUE) uses standardized breathing mixtures for various depth ranges and for decompression. Here British wrecker and instructor evaluator Rich Walker gets lyrical and presents the reasoning behind standard mixes and their advantages, compared with a “best mix” approach. Don’t worry, you won’t need your hymnal, though Walker may have you singing some blues.

Rules of Thumb: The Mysteries of Ratio Deco Revealed
Is it a secret algorithm developed by the WKPP to get you out of the water faster sans DCI, or an unsubstantiated decompression speculation promoted by Kool-Aid swilling quacks and charlatans? British tech instructor/instructor evaluator Rich Walker divulges the arcane mysteries behind GUE’s ratio decompression protocols in this first of a two part series.

The Thought Process Behind GUE’s CCR Configuration
Global Underwater Explorers is known for taking its own holistic approach to gear configuration. Here GUE board member and Instructor Trainer Richard Lundgren explains the reasoning behind its unique closed-circuit rebreather configuration. It’s all about the gas!

GUE and the Future of Open Circuit Tech Diving
Though they were late to the party, Global Underwater Explorers (GUE) is leaning forward on rebreathers, and members are following suit. So what’s to become of their open circuit-based TECH 2 course? InDepth’s Ashley Stewart has the deets.

Diving projects, or expeditions—think Bill Stone’s Wakulla Springs 1987 project, or the original explorations of the Woodville Karst Plain’s Project (WKPP)—helped give birth to technical diving, and today continue as an important focal point and organizing principle for communities like Global Underwater Explorers (GUE). The organization this year unveiled a new Project Diver program, intended to elevate “community-led project dives to an entirely new level of sophistication.” Here, authors Guy Shockey and Francesco Cameli discuss the power of projects and take us behind the scenes of the new program

Decompression, Deep Stops and the Pursuit of Precision in a Complex World In this first of a four-part series, Global Underwater Explorers’ (GUE) founder and president Jarrod Jablonski explores the historical development of GUE decompression protocols, with a focus on technical diving and the evolving trends in decompression research.