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Counting DecoBubbles: A Crowdsourcing Initiative For Diving Research
Frauke Tillmans and Virginie Papadopoulou and their team need YOUR HELP counting bubbles! Their goal: to develop an automated algorithm to detect and score venous gas emboli (VGE). It’s a new crowdsourced research initiative from Divers Alert Network (DAN) in collaboration with the Department of Biomedical Engineering at UNC Chapel Hill & NC State University. Welcome to Counting DecoBubbles.

By Frauke Tillmans and Virginie Papadopoulou
Header image courtesy of the authors
What do DAN researchers do during a pandemic with few diving opportunities? We put the final touches on our new diving research app, of course! The research team at the Divers Alert Network (DAN) and Department of Biomedical Engineering at UNC Chapel Hill & NC State University, together with a handful of collaborators worldwide, is proud to present DecoBubbles.com.
Venous gas emboli (VGE) are decompression bubbles that are detectable on ultrasound imaging in the blood of some divers for several hours after a dive. Higher loads of VGE are associated with a higher risk of decompression sickness (DCS), but the relationship is not linear. Differences in VGE and DCS risk have been documented among individuals and in the same individual—even with identical dives. Importantly, VGE evolution post-dive varies dramatically, so getting frequent measurements can help us study the influence of VGE on other physiological mechanisms in diving. Toward this goal, we are refining automated algorithms for VGE detection.
We have developed an online application where anyone can volunteer their time to help locate bubbles in post-dive echocardiograms. This will help us build robust machine-learning algorithms to automate this task and accelerate the pace of decompression research to improve our understanding of how these bubbles are related to decompression sickness and human physiology.
This project has also provided training opportunities for the numerous students involved at various stages of the research development. Read on to learn about the first “dive into research” on the part of our lead developer Martin Smolka, a computer science senior at UNC! And be sure to register here to start counting bubbles: DecoBubbles.com.
Creating a Crowdsourcing Research Tool
By Martin Smolka
I am a senior at UNC Chapel Hill where I am finishing my bachelor’s degree in computer science. A year ago, a friend forwarded an email to me about a diving lab that was looking for someone to build a website. I uttered the famous last words, “How hard can it be?”, and sent over my resume.

Looking back, after working with this team for more than a year now, I find it funny how quickly I found myself in over my head. To this day, the closest I have ever been to diving was when I was 10 years old and angry that the deep end of the local YMCA pool was closed off for diving training. Combine this with the rude awakening that completing a three-month internship at a tech company does not automatically make me an expert web developer, and you can see my dilemma.
The one thing I did have going for me was that I knew so little, I never knew how in over my head I truly was at any given time. Now, a year later, I am happy to announce that the website is live on Decobubbles.com. Building this site has been the most difficult and most rewarding aspect of my journey to earn my undergraduate degree.
Decobubbles.com is the latest chapter in my team’s story to personalize decompression procedures. Currently, decompression procedures are successful at reducing the risk of decompression sickness (DCS); however, they follow a one-size-fits-all approach, and cannot predict if an individual diver is likely to develop DCS. While two divers can make the same dive and follow the same decompression procedures, one may develop DCS, and the other will not.
DCS results from decompression bubbles growing during and after the diver ascends to the surface, but the majority of divers with bubbles do not develop DCS. My team, known as “Team Scuba” around the biomedical engineering department, in collaboration with DAN, researches these bubbles and is currently optimizing their detection using ultrasound imaging. Ultrasound imaging is widely used in diving research to detect circulating bubbles post dive; the VGE appear as bright spots moving through the chambers of the heart. We are researching these bubbles because we believe that they can help personalize decompression procedures.
To study how divers’ physiology responds to dives, we collect multiple ultrasounds of divers’ hearts (echocardiograms or “echos”) for several hours post dive. The reason we take so many echoes is because the amount of decompression bubbles, aka decobubbles, can vary dramatically over time and the dynamics of those changes could offer new information for our research.
Collecting each echo is relatively easy and takes less than a minute; however, determining how many bubbles are present in an echo is more complicated. While this is a pretty simple process for medically trained personnel, it is difficult to get a cardiologist to review the thousands of ultrasounds one of our experiments can produce. So, Team Scuba began to focus on ways to streamline the process of determining how many bubbles are present in echos.

I’m Forever Counting Bubbles
The process of “bubble counting” was developed to easily quantify bubbles on echocardiography. Bubble counting can be done by anyone with relatively little training. While easier, bubble counting started out much slower, taking well over eight minutes to count a 20 second video by hand. This process now takes around three to four minutes thanks to a previous undergraduate student’s work building a computer interface that automates many of the time-consuming aspects of the method. This program has greatly increased the volume of data a given research team can analyze in the context of their own experiments, but is not ideal for sharing the analysis of a large amount of data between people located in different parts of the world.

This is where my chapter of the story begins. I was brought onto the team to bring the echo rating program to the web for easy sharing and crowdsourcing. Starting out, while I was very excited about working on this project, I was even more excited at the prospect of not being completely broke on the weekends. Then, when I began to start researching what would be necessary to pull off this task, the weight of the task started to crush a good portion of the initial excitement.
What makes this website much more complicated than the previous rating program is that everything needs to be done through the cloud. Whereas many things, like determining what video to show the rater, and determining who could use the program, were trivial on the old program, I would now have to design systems to run on the cloud to accomplish these tasks. I had never attempted to build systems as complicated as these before, and I had no idea where to even begin. I would spend many hours with a pen and paper just drawing out the process behind the systems, and eventually I would think I had a winner. Then I would spend the next few days implementing the idea and spend the next month finding all the little bugs and mistakes in my strategy. Creating Decobubbles.com was a slow and tedious process, so I am ecstatic that it has finally come together.
While I spent countless hours learning and implementing new technologies, the most difficult thing by far was creating the tutorial. This was not only difficult for me technically, but also difficult conceptually. It took me a long time to create a system to train and test new raters; however, it took me much longer to actually create the tutorial video.
When I started creating the tutorial, I naively thought I was a bubble counting expert since I spent hours glancing at echos while I was building the website. I quickly figured out that being able to make out a few bubbles on an echo and having the knowledge to teach someone how to rate an echo were two separate things
When I started creating the tutorial, I naively thought I was a bubble counting expert since I spent hours glancing at echos while I was building the website. I quickly figured out that being able to make out a few bubbles on an echo and having the knowledge to teach someone how to rate an echo were two separate things. I find it very funny that my process to learn how to rate an echo was creating a tutorial to teach others how to rate echos. This had one big benefit, however. I knew what aspects would be confusing to new raters because those aspects were still confusing to me. Then I was able to take those confusing aspects and explain them further in a way that even I, a complete novice, would understand. All in all, I am very happy with how the tutorial turned out and glad to have learned so much through the process.

The story of personalizing decompression procedures did not start with me; nor will it end with me. In the next chapter, the team will pull the data generated from decobubbles.com to train an artificial intelligence (AI) to automate the echo rating. Automated echo rating would mean that the team can conduct experiments while no longer constrained by the capacity of echo rating and will be able to generate more data than ever before. This data will become a major part of our larger goal to target decompression procedures to individual physiology and could eventually be loaded onto dive computers as personalized algorithms. AI might even be used again to aid in this task because of its ability to find patterns and correlations in large and complex datasets!
My contribution to this story is quickly coming to an end as the days until my graduation continue to count down. After I graduate, I plan to get a job using the skills I have developed working on Decobubbles.com by writing software. The research environment allowed me to take extra time to learn new technology and to develop as a programmer.
One great way to learn about echocardiography and aid in research is to log onto decobubbles.com. Each rating that you submit will aid our efforts to better understand DCS and produce personalized decompression procedures.
One great way to learn about echocardiography and aid in research is to log onto decobubbles.com. Each rating that you submit will aid our efforts to better understand DCS and produce personalized decompression procedures. So, help me end my project on a high note by checking out Decobubbles.com today!
Funding:
This crowdsourcing project is funded by the Divers Alert Network (grant #DAN-UNC-1), and analyzed data is being fed into the collaborative project, “Automating the detection of post-dive venous gas emboli” funded by Department of the Navy, Office of Naval Research (grant #N00014-20-1-2590), bringing together DAN, UNC, Duke and UCSD.
References:
Nishi RY, Brubakk AO, Eftedal OS, Bubble detection, in Bennett and Elliott’s physiology and medicine of diving, A.O. Brubakk and T.S. Neuman, Editors. 2003, WB Saunders: Philadelphia, PA. p. 501-29.
Eftedal OS, Lydersen S, Brubakk aO. The relationship between venous gas bubbles and adverse effects of decompression after air dives. Undersea and Hyperbaric Medicine, 2007. 34(2): p. 99-105.
Papadopoulou V, Eckersley EJ, Balestra C, Karapantsios TD, Tang MX. A critical review of physiological bubble formation in hyperbaric decompression. Advances in Colloid and Interface Science, 2013. 191-192: p. 22-30.
Le DQ, Dayton PA, Tillmans F, Freiberger J, Moon R, Denoble P, Papadopoulou V. Ultrasound in Decompression Research: Fundamentals, Considerations, and Future Technologies. Undersea and Hyperbaric Medicine. 2021;48(1):59-72.
Markley E, Le DQ, Germonpre P, Balestra C, Tillmans F, Denoble PJ, Freiberger JJ, Moon RE, Dayton PA, Papadopoulou V. A fully automated method for late ventricular diastole frame selection in post-dive echocardiography without ECG gating. Undersea and Hyperbaric Medicine. 2021;48(1):73-80.
Papadopoulou V, Germonpre P, Cosgrove D, Eckersley RJ, Dayton PA, Obeid G, Boutros A, Tang MX, Theunissen S, Balestra C. Variability in circulating gas emboli after a same scuba diving exposure. European Journal of Applied Physiology, 2018. 118(6): p. 1255-1264.
Papadopoulou V, Tillmans F, Denoble P. Call for a multicenter study on the intra-subject variability of venous gas emboli. Undersea and Hyperbaric Medicine, 2017. 44(5): p. 377.
Vann RD, Butler FK, Mitchell SJ, Moon RE. Decompression illness. Lancet, 2011. 377(9760): p. 153-64.
Sawatzky, K.D., The relationship between intravascular Doppler-detected gas bubbles and decompression sickness after bounce diving in humans, 1991, York University: Toronto, ON.
Papadopoulou V, Lindholm P. An Echo from the past; building a Doppler repository for big data in diving research. Undersea and Hyperbaric Medicine. 2021;48(1):57-58.
Dive Deeper:
Here are some of the DAN research projects in the works:
Comparative Testing of Ultrasound Devices in Monitoring VGE
Exploring Decompression Bubbles Using Advanced Ultrasound Techniques
InDepth: Retired French Naval officer Axel Barbaud and his team have developed an automated bubble scoring algorithm for doppler readings: Oh Deco, Oh Doppler, O’Dive: Assessing the World’s First Personal Deco Safety Tool
InDepth: Everything You wanted To Know About PFOs and Decompression Illness, But Were Too Busy Decompressing to Ask by Dr. Doug Ebersole

Dr. Frauke Tillmans is the Research Director at Divers Alert Network (DAN). She has a PhD in Human Biology and oversees DAN’s research initiatives in injury monitoring and diving physiology, including acute diving injuries, as well as long-term health effects of diving and extreme exposures. Throughout her career she has participated in projects covering a variety of medical aspects in recreational and military diving. An avid and well-travelled diver herself, she has become DAN’s point of contact for global scientific collaborations, including the newest addition, “DecoBubbles”.

Dr. Virginie Papadopoulou is a Research Assistant Professor in the Joint Department of Biomedical Engineering at the UNC Chapel Hill & NC State University. Her research aims to bridge the different areas dealing with bubbles in the bloodstream, from environmentally triggered endogenous bubbles, to engineered contrast agents for ultrasound imaging and therapy. She has been awarded the 2017 Divers Alert Network/Bill Hamilton Memorial Grant by the Women Divers Hall of Fame, the 2020 Undersea and Hyperbaric Medicine Young Scientist Award, as well as the title of Divers Alert Network Scholar since 2018, for her on-going work creating a dynamic ultrasonic assessment of decompression bubbles.

Martin Smolka is a Senior at The University Of North Carolina at Chapel Hill where he is finishing up his bachelor’s in computer science. Martin has experience with building modern web applications and works as an undergraduate researcher on Dr. Papadopoulou’s team to build and maintain DecoBubbles. He designed and developed the application using Google’s Angular Framework and developed the structure of the database in Firebase.
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.