Education
Part Two: “Tech Divers, Deep Stops, and the Coming Apocalypse”
In part two of this four-part series on the history and development of GUE’s decompression protocols, GUE founder and president Jarrod Jablonski discusses the lack of appropriate mixed gas decompression tables in the early days of technical diving. He goes on to discuss the initial development of “ratio decompression” and the early thinking and rapid adoption of “deep stops,” which have come under pressure as a result of new research that questions their efficacy and safety. He also discusses the emergence of the now nearly ubiquitous gradient factors (GF) used in most dive computing. Feel free to DIVE IN and share your thoughts.
by Jarrod Jablonski
Header Photo by JP Bresser
Technical diving means different things to different people, opening legitimate arguments about different time periods and personalities involved in shaping this activity. Our purpose is more confined as I wish to focus mainly upon the development of decompression procedures. Leading figures like Jacques Cousteau (1910–1997) performed reasonably significant “technical” dives including both deep and overhead exposures. Yet, his dives were relatively short, often on air, and absent a community of fellow tech divers with whom to evolve varying strategies. Meanwhile, military or commercial activities reached significant depth with notable exposures but used different technologies and procedures. Hopefully, the following overview will be independently interesting—although I also hope to illustrate what I consider an intriguing wrinkle currently lacking in most debates over the best ascent schedule for a decompression dive.
For our purposes, I mark the 1980s as the period in which technical diving truly started to become a globally recognized activity. Of course, numerous significant projects occurred before this period, but the 1980s established a growing global awareness that amazing diving feats were possible by enthusiasts. The 1990s and the developing internet age brought these ideas progressively into the mainstream. Most importantly, these global communities could now easily communicate information and, of course, disagree about the best way to do one thing or another.
The 1980s and 1990s were also an interesting period of development because people were doing more aggressive dives but still lacked important support tools that would take another decade to materialize. For example, most early tech dives were using some form of military, commercial, or scientific tables, such as the U.S. Navy, Oceaneering International, Inc. or the National Oceanic and Atmospheric Administration (NOAA), which were often not well-suited to the dive at hand. This is because there were no decompression programs available. Divers were unable to calculate their own profiles and would trade whatever tables they could gather. In many cases, they were forced to choose from tables that were calculated at a different depth, time, and/or breathing mix to the planned dive.
Over time, the physiologist Dr. R.W. “Bill” Hamilton (1930–2011) began creating custom tables, but the lack of flexibility, as well as the cost, discouraged frequent use for most divers, especially when considering a range of depth profiles and their various time adjustments. This problem was especially prominent in deep cave diving where variable profiles and long bottom times created numerous complications . This landscape encouraged, if not demanded, that exploration divers be creative with their decompression practices. For example, Woodville Karst Plain Project (WKPP) explorers George Irvine and I began to explore ways to extrapolate from existing tables. The birth of what is now called ratio decompression originated with this practice.
By exploring the way decompression schedules develop, we began outlining simple ratios that allowed divers to adjust their decompression based upon a ratio of time spent at depth. Then, in 1998, I went on to form Global Underwater Explorers (GUE), and such practices became part of the process for helping divers appreciate the structure of decompression while supporting adjustments to profiles when depth or time varied from that expected. Regrettably, some individuals took this too far and began promoting complex adjustments and marketed them as superior to the underlying algorithms from which they had been derived.
We should leave a more in-depth review of ratio deco for another time. For now, I intend to illustrate that “rules” such as ratio deco had their roots in limited availability of decompression tables and evolved as a useful tool for understanding and estimating decompression obligation. The fact that early tech divers had limited ability to calculate profiles encouraged a “test-and-see” philosophy, further fueling the early popularity of ad hoc adjustments to decompression profiles. This was most notable in the DIR and GUE communities through ratio-style adjustments and also prominent with non-DIR advocates who used a modification known as Pyle-stops, originating from ichthyologist Richard Pyle’s early deep dives and his attempts to refine efficient ascent protocols. One common adjustment in these approaches involved a notable reduction in ascent speed, adding additional stops known as “ deep stops ”
Driven by self-discovery, the migration toward deep stops resulted in rare agreement among technical divers, and the practice developed a life of its own in conference symposiums, being advocated far and wide by a healthy share of technical divers. The earliest phases of these modifications were driven in part by limited access to decompression tables, though by the end of the 1990s there were a variety of decompression programs available. This was a big improvement, although it was still true that divers had a limited baseline of successful dives while planning mixed-gas dives in the 50 to 100 meter range and beyond. Today, most divers take for granted that technical dives planned with available resources and within today’s common use (a few hours around 90m/300 ft) are relatively safe in terms of decompression risk. When these programs first came to market, there remained many question marks about their efficacy.
The availability of decompression programs was a big advantage for technical divers, as they now had more sophisticated tools at their disposal. Yet, the output from many of these programs produced tables that were sometimes different to profiles thought to be successful by some groups. Typically, the difference related to an increase in the total decompression time and/or a distribution of stops that varied from developing consensus. These divers were keenly interested in the developing tools but reluctant to change from what appeared successful, especially when that change required additional hours in the water. A debate developed around the reason for these differences, bringing the already brewing interest in bubbles well into the mainstream.
At the time, all tables were based upon dissolved gas models like Buhlmann, and thus not directly modeling bubble development during an ascent. Dissolved gas models preference ascents that maintain a reasonably high gradient between the gas in tissues and the gas being breathed, which should be supportive of efficient elimination from tissues. Dissolved gas models manage—but do not explicitly control for—bubbles and were thus labeled (probably unfairly) as “bend and mend” tables. In fact, dissolved gas models are designed to limit supersaturation (explicitly), because this is supposed to limit bubble formation. Haldane references this control of supersaturation in his pioneering publication .
Those advocating for different ascent protocols imagine that a lack of deep stops creates more bubbles, which then need to be managed during a longer series of shallow decompression stops. In this scenario, a slower ascent from depth, including “deep stops,” would reduce the formation and growth of bubbles while reducing time that might otherwise be needed to manage previously formed bubbles. Support for these ideas gained momentum in diving and professional communities, although some of these individuals were arguably conflicted by a vested interest in promoting deep stop models. Eventually, the practice received more critical consideration but during the intervening years deep stops were largely considered as common knowledge.
The idea of controlling bubbles became extremely popular through the 1990s, encouraging deeper stops designed to limit bubble formation and growth. The “test-and-see” approach developed by early tech divers appears to have fueled the promulgation of deep stops though the determining characteristics remained poorly defined. Early tech divers embraced the uncertainty of their activity, realized that nobody had the answers, and decided to “experiment” in search of their own answers. In fact, divers were experimenting with a lot more than deep stops, altering gases breathed, the placement of various decompression stops, and the total amount of decompression time utilized. This meant that divers were sometimes aggressively adjusting multiple factors simultaneously.
For example, divers using a decompression program might input significantly less helium than was present in their breathing mixture. This was done because the algorithm increased decompression time with elevated helium percentage, sometimes known as the helium penalty . In other cases, divers would completely change the structure of stop times. For example, divers would invert the way a profile should be conducted by doing more time near a gas switch and less time prior to the next gas switch, believing the higher-oxygen gas only 3m/10ft away was time better utilized.
I do not intend an exhaustive or detailed review but only to assert the many, sometimes radical approaches being taken by tech divers who often perceived success with these various strategies. In some cases, it appears these practices may have been leading the way toward improvements (eliminating the Helium penalty) while other adjustments might prove disadvantageous. In both cases, it is important to note that divers understood—or should have understood—these actions to be potentially dangerous, accepting risk as a natural part of pushing into uncertain territory where definitive guidance and clear borders are rarely available.
None of this is to argue that divers should engage in aggressive decompression or challenge convention or place themselves at risk to unknown complications. I merely wish to clarify the atmosphere under which these adjustments were conducted, while highlighting that conventional ideas of risk mitigation are inherently complicated against a backdrop of novel exploration. A sense of relative risk dominated most of these trials since there are also risks associated with lengthy, in-water exposure. Eliminating what might be an avoidable decompression obligation could reduce risk from other obvious factors, including changing weather, dangerous marine life, being lost at sea, hypothermia, and oxygen exposure. Decompression experimentation was but one of many attempts to establish new protocols during extensive exploration projects.
During this time, deep stops and similar adjustments were part of the “norm” for aggressive technical explorers who were sometimes notably reducing in-water time as compared to available tables. It is interesting to note that individual differences in susceptibility seemed among the most prominent variables across the range of tested adjustments, and we will return to this in a later discussion. For now, we should acknowledge that the “success” being achieved (or imagined) is greatly complicated by a small sample size of self-selected individuals who were simultaneously experimenting with a range of variables. On the other side, I do not want to entirely discount the results being seen by these divers. We should remember that development of safe decompression ascents for the general diving community was not the goal of most tech divers. These divers were interested in maximizing their personal and team efficiency during decompression. These strategies may or may not have been objectively successful or broadly applicable, but many teams imagined them so, at least within the narrow scope being considered. Later, we will return to these important distinctions with careful consideration for the potentially different interests being pursued by divers evaluating different decompression profiles.
Fortunately, a desire to create broadly useful tools was high on the list of priorities for some individuals in the technical diving community, leading to a relevant and important contribution. This inventive approach would introduce a new way to think about decompression, remaining to this day at the center of the debate about deep stops.
Creating a New Baseline
Despite the popularity of deep stops and other modifications presented previously, technical divers lacked a common language for comparing the results, especially across different profiles. Compounding this problem was the variable way decompression programs considered a dive to be more or less “safe.” For example, some programs developed “safety factors” which increased total decompression time by an arbitrary factor, i.e., made them 10% longer. Other programs used different strategies, though it was not clear whether any of the various safety factors actually made the decompression safer. Whether safer or not, these factors were typically inconsistent and added complications when comparing various profiles. Just as these debates were reaching a fervor, help arrived from an unlikely place. An engineer by trade and decompression enthusiast by choice, Erik Baker had developed a novel solution.
Baker was seeking a way to establish consistency in considering the safety or lack of safety between various profiles. The term Baker applied was Gradient Factor (GF). I will not invest considerable time exploring the science behind GF, as many useful resources are widely available. For our purposes, it is sufficient to say that GFs allows a user to establish a lower threshold than the maximum recommended by a dissolved gas algorithm. This maximum pressure or M-value is assigned to “compartments” having an assumed amount of tolerance relative to the flow of blood they receive. Decompression theory is complicated by many factors but when the pressure of a gas in a compartment nears the M-value, it is thought that the risk of decompression sickness becomes higher. By adjusting a profile through the use of GF, one presumably reduces the risk. However, this also means there is less gradient between the gas in tissues and the gas in blood, reducing the driving force for the removal of gas and probably requiring additional decompression time.
Gradient factors took an important step toward using a consistent language when talking about a variety of adjustments divers might make to their decompression. As part of his work on GF, Baker had developed a keen interest in the decompression adjustments by leading technical divers. Baker and I began working together while evaluating some of our most extreme diving profiles. This collaboration led to a number of productive developments including GUE’s DecoPlanner, released in 1997, and among the first to utilize GF methodology. These collaborations further highlighted what appeared to be a discrepancy between the decompression expected by dissolved gas algorithms and the decompressions being conducted by many technical divers.
Decompression experimentation tended to cluster in small groups whose size was likely affected by self-selection with members who would stop or reduce aggressive dives when experiencing decompression sickness. Yet, it seemed possible that there was more to the story. These divers were doing several things that should have exposed them to notable risk and yet were repeatedly completing decompressions of more than 15 hours. Deep stops were only part of the story as these divers were ignoring conventional wisdom in several areas while notably reducing decompression time. What was behind this discrepancy? Were deep stops right or wrong? Was the conservative approach to helium right or wrong? Were these individuals lucky? Were they unusually resistant to decompression sickness, or were there other factors lurking in the background?
Note: I will outline many of these developments in the upcoming Part Three, where we more directly consider the modern challenges to deep stops and most especially the assertion they are dangerous. In the interim, I hope to hear from our readers. Do you have different experiences from this period? Do you think such experimentation is reckless or inadvisable? Please let us know your thoughts.
Read the other articles in the series:
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.
Education
The Way The World Will Learn to Tec: Exploring PADI’s TecRec Update
By Michael Menduno. The views and opinions expressed are strictly my own. Photos courtesy of PADI unless noted.
This October at the annual Diving Equipment & Marketing Association (DEMA) tradeshow, PADI released a long-awaited update to its open circuit “TecRec” program, which was originally launched in 2001. Specifically, the training juggernaut has completely rewritten its introductory courses to tech diving, i.e., its Tec 40, 45, and 50 courses that serve as the gateway between recreational and technical diving.
The update incorporates the latest diving science and thinking on topics such as gas density, gradient factors and deep stops, the helium penalty, whether oxygen is narcotic, dive planning software, and more. It enables divers to do their training in sidemount or backmount, adds additional “dry” practice session options into courses, and now offers trimix as a gas option beginning at 40 m/130 ft—originally the program was air and nitrox only.
In addition, PADI added a Discover Tec (try-dive) and Tec Basics (skills) courses as additional resources for would-be tekkies and instructors. PADI’s advanced trimix courses, Tec 65 and Tec Trimix (which are newer) and its closed circuit rebreather (CCR) program (which was launched in 2012) remain largely unchanged. The updated TecRec courses are available now, though the original courses can be taught until 2025.
“We think it’s the most robust and comprehensive program on the market,” PADI’s Michael Richardson, a Supervisor for Instructor Development, boldly asserted to me at the show. His comment got my attention, and I was interested to know more.
The TecRec update signals a conscious move on PADI’s part to lean forward into Tec diving and make it more accessible to interested recreational divers, while providing increased flexibility and resources for instructors and dive centers to expand their technical diving business. As discussed in PADI’s member materials, though tech divers only represent about 7% of recreational or sport divers, they are not only more engaged but spend considerably more money on equipment and training—as we know!—making them a lucrative market niche. “Tech diving is the future of the market,” opined Asutay Akbayir, PADI Regional Manager for the South Mediterranean, who has been involved in the TecRec program since its inception.
In fairness, though PADI is not regarded as tech brand, its sheer size and market presence with 128,000 members (instructors and dive masters), 6,600 dive centers in 184 countries, and (according to PADI) an estimated 70% of the open water market—The Way the World Learns to Dive—makes them an important player in the tech market.
Though they declined to answer me specifically, PADI likely has upwards of 4-5,000+ Tec and rebreather instructors at various levels (personal communications)—second only to Technical Diving International (TDI)—and sports at least 366 designated TecRec centers in 64 countries, though many more dive centers offer tech training. And though they also declined to answer my questions on certifications, PADI is probably responsible for having brought tens of thousands of new tekkies, well, in this case, “Teccies,” into the fold.
By focusing on the transition from Rec to Tec—arguably an area of strength for PADI which dominates the recreational market—the training giant will not only help create more tech divers but likely stands to grow the market—The Way Many Will learn to Tec? —and in doing so gain market share. They will also likely gain Tec instructors. According to PADI, 55% of all technical diving instructors globally are also PADI professionals, which means that the organization has direct links to those that can potentially help grow its tech training business.
PADI’s prospects for picking up new business are arguably further enhanced by the high quality of PADI’s new Tec eLearning materials and standards which seem to combine the best of old-school tech with the latest developments. Though some tekkies seem to enjoy PADI bashing—ironically both PADI and Global Underwater Explorers (GUE), which hosts InDEPTH, seem to be favorite targets for critics, though for different reasons—most tech professionals will likely be impressed by PADI’s latest efforts, which were more than two years in the making. I know I was.
Accordingly, here is a brief review of the history of PADI’s TecRec program and a discussion about some of the details of the new update.
A Dive into Tec History
PADI’s Diving Science and Technology (DSAT) division released its Tec Deep Diver program in 2001. The general approach at the time was to treat technical diving like cave diving, in that it shouldn’t be promoted, but if people were interested, the training was available. Note that DSAT, which served as PADI’s tech division for a time, was also a sponsor of Rebreather Forum 2, held in Redondo Beach, CA in 1996, and published the Proceedings.
Tec Deep Diver was an extensive course, typically taught over an extended time, with numerous days and or weeks devoted to training. It included 12 air or nitrox dives to a max depth of 50 m/165 ft, and a dense 378-page manual. By comparison, an Intro to Cave followed by Full Cave course today, would generally run 8-10 days and include 16 dives. In about 2009, the Deep Diver course was broken up into three modules: Tec 40, Tec 45, and Tec 50, indicating maximum course depth in meters, but the content remained largely unchanged.
Instructors I asked told me that the Deep Diver course was challenging to teach. First, the time requirements meant it was very difficult to fit into student and instructor schedules. Breaking the course into modules helped some, but the sheer volume of content was daunting. The course was developed when mixed gas dive computers and dive planning software were still in their infancy, so students were left to deal with extensive math calculations with a pen and calculator.
The original course was also conducted solely on air or nitrox blend. In fairness, back in the day, the community, by and large, limited air diving to 57 m/187 ft, based on a PO2=1.4 bar, and considered narcotic levels manageable at those depths. It was only later, pioneered primarily by GUE, that the recommendation to maintain Equivalent Narcotic Depths (END) at 30 m/100 ft by adding helium to the mix.
As a result of the further work on gas density, Dr. Simon Mitchell and Gavin Anthony, concluded that air diving be limited to less than 40 m (gas density less than 6.3 g/l). To be sure, PADI received internal and external feedback and scrutiny over the last few years regarding their approach to what is now considered “deep air” diving, and deep air diving with students. They were not alone. Their new recommended trimix options address this.
Finally, the original course material became seriously out-of-date with regard to important new developments in diving science and safety, including gas density as mentioned, gradient factors and deep stops, narcosis levels, the helium penalty, whether oxygen is narcotic, Immersion Pulmonary Edema (IPE), using dive gauges and tables versus dive computers, the use of dive planning software, and more.
Course Structure and Logistics
As far as the requirements for the courses, Tec 40 requires a PADI Advanced Open Water and Enriched Air Diver certification (Rescue Diver is recommended), the Deep Diver certificate or at least 10 dives to 30 m/100 ft, and at least 30 logged dives. The student must be at least 18. Tec 45 requires Tec 40, an additional Rescue Diver certification, and a minimum of 50 dives (≥10 dives to at least 30 m/100 ft). Tec 50 requires Tec 45, and a minimum of 100 dives or 75 hours. No doubt, a discussion could be had on how much experience someone should have before starting on their tech journey.
Course specifications are as follows: Tec 40 can be conducted on a single tank provided it has a Y-valve for redundancy, or backmount or sidemount doubles, depending on the students’ certifications, along with up to one deco gas with a maximum of 50% oxygen. The course includes four dives to α max depth of 40 m/130 ft with a maximum of 10 minutes of decompression on back gas, or 15 minutes using deco gas. The course has a trimix option with a minimum of 21% O2 and a maximum of 35% helium.
Tec 45 is conducted in doubles back or side mounted cylinders and one deco gas up to 50% O2, with four dives to a maximum depth of 45 m/148 ft and a trimix option. There are no decompression time limitations. Tec 50 also consists of four dives to a maximum depth of 50 m/165 ft with double cylinders, two deco gases, one of which can contain up to 100% O2, and (optionally) normoxic trimix, with no more than 40% helium. Again, there are no specified deco time limits.
The courses, which are performance based, intentionally have a lot of flexibility in scheduling using eLearning or class presentations (depending on language), however a typical schedule might be 3-4 days for each course, depending on the needs of the students. The instructor may also begin with the Tec Basics module to bring up divers’ skills prior to beginning the Tec 40-50 sequence.
Courses include an “Instructor Wetbook” for each class that instructors can take in the water as part of their tool kit. The Wetbook essentially outlines the conduct of the course and includes performance goals, checklists, skills to be learned, specifications for conducting each dive, etc. It is the only physical learning material used in the courses.
Taken as a whole, the Tec 40, 45, and 50 courses represent a comprehensive introduction to technical diving consisting typically of 9-12 days of training and 12 dives. To put this into perspective, by comparison earning a “tech pass” in a GUE Fundamentals class followed by a GUE Tech 1 course (dives to a max 50 m/165 ft depth with trimix 21/35, one deco gas (up to 100% O2) and a maximum of 30 minutes of deco), typically would require 10 days of training and 13 dives. So, the two are roughly equivalent in terms of training time and number of dives.
My Impressions
I decided the best way to assess the new courses was to dive in and work through the eLearning modules. It should be noted that PADI pioneered the use of eLearning in diving, back when digital meant floppy discs. Remember them?
I was impressed that the authors were able to seamlessly weave together old school tech philosophy and approach with the latest diving science with a focus on diver safety. Overall, it was some of the best tech course material I’ve read.
Tec 40 begins with a sobering warning.
To sum up the difference between recreational and technical diving risk in a single statement: “In technical diving, even if you do everything right, there is still a higher inherent potential for an accident leading to permanent injury and death. You have to accept this risk if you venture into technical diving. “
The warning is straight out of the original tech playbook pioneered by Capt. Billy Deans, before there were formal tech certification classes. Back in the late 1980s/early 1990s, interested divers traveled to Key West to spend a week, 10 days, two weeks—as much time as they could spare—to learn mixed gas diving from Capt. Billy. This was before formal tech certification courses existed.
By way of background, Deans’ best friend John Ormsby died on a deep air dive on the Andrea Doria in 1985. Deans was one of the divers that recovered the body and brought it back to the RV Wahoo. The incident motivated Deans, who worked with Dr. Bill Hamilton, to swear off “deep air diving” and develop his mixed gas diving operation and offer training.
On the opening day of his classes, Deans would welcome everyone. “We’re here to have a good time, “ he would say. “But before we do, I need to have your attention.” He would then play the film of him and others recovering his friend’s lifeless body and hoisting it onto the back deck of the Wahoo. “As I said, we’re here to have fun, but this is serious. You have to pay attention, and do everything right—there’s no room for complacency. If you don’t, you’re going to die.” Deans was admittedly harsh by today’s standards, but his admonition never failed to get divers’ attention.
It was encouraging to see attitudinal requirements and discussions as an integral part of the course. Attitude requirements were of course, part of original “Blueprint for Survival 2.0” community consensus of best tech diving practices that was published in aquaCORPS Journal #6 COMPUTING (June 1993), and meant to help improve tech diving safety.
To quote the Tec 40 text, “Your actions, words, and behavior must reflect that you will choose to follow the procedures, rules, and principles you learn in this course. This attitude is considered particularly important to diver safety in technical diving.”
In fact, Tec 40 offers six characteristics that denote a responsible technical diver, to wit; self-sufficiency, team player, disciplined, wary, physically fit, accepts responsibility. Sounds about right to me.
Finally, in the wrap up, the Tec 40 text reminds would-be tekkies (paraphrasing), “Your primary mission in tech diving is to survive the dive!”
Absolutely!
It’s The Science, Stupid
As mentioned above, the Tec course materials integrate the latest science and thinking from gradient factors and gas tolerance to IPE and offer depthful and nuanced discussion. The latest science, for example, has concluded that oxygen is non-narcotic in the PO2 relevant ranges for tech diving, however, the discussion points out that there’s nothing wrong with adding extra conservativeness and treating both O2 and N2 as narcotic gasses in calculating one’s END.
Similarly, the material teases out the nuances of the so-called “helium penalty,” a feature of some decompression algorithms that add extra deco time when using helium, whether or not it’s physiologically needed, and what that means for tech divers. They have also eliminated “deep stops,” which were included in the original Deep Diver course and offer an explanation why.
I was also impressed with the level of detail. For example, in discussing gear configuration, the text points out that tekkies don’t use hose protectors because they can mask hose damage. Similarly, in discussing the use of hyperbaric mixes, it details the risks of oxygen fires, the need for proper cleaning and lubrication, and even highlights the fact that regulators made with titanium might not be fully compatible with oxygen use (check with the manufacturer).
As mentioned, the mathematics and calculations sections focus on using dive computers and dive planning software to arrive at the answers rather than doing manual calculations. Hmm, it’s faster and more accurate. PADI calls it a “real world” consideration. Geeks like me can follow the link to the formula details and calculations, if that’s what they need to learn the material.
Drills & Skills
The Instructor Wetbooks outline the drills and skills to be worked during both dry and in-water sessions. I found them to be quite comprehensive and included the drills and skills you’d expect; dive planning, pre-dive checklist and equipment matching, S-drill, bubble check, controlled descent, propulsion drills, valve drills in trim, putting on and removing stage bottles, regular SPG checks, gas sharing, SMB deployment and ascent practice, proper gas switching, calculating SAC rates, etc.
As they work their way through the courses, students spend increasing time on problem-solving and responding to team emergencies such as free flows and leaky valves; various out of gas scenarios (bottom gas, deco gas); dealing with a dive buddy breathing the wrong gas at depth; buoyancy device failures; dive computer failures; and rescuing an unconscious diver. GUE Tech students will be very familiar with these kinds of drills.
Recommendations & Standards
I found the recommendations and standards presented in the courses robust and reassuring, and if offering a recommendation vs. making it a requirement is insufficient to satisfy a dyed-in-the-wool, old-school GUE instructor, it would likely at least get her to at least give a nod of support. One of the considerations for PADI, with its ginormous, global scale, is that courses must have sufficient flexibility to meet the needs of divers and instructors in different geographies. Here are some of the high points.
PADI recommends that tech divers maintain an END ≤30 m/100 ft and gas density less than 6.3 g/l (the air equivalent of 38 m/128 ft); however, it does not mandate the use of trimix for the Tec 40-50 courses. Given current prices and availability issues with helium, it is recommended but optional in these ranges, depending, of course, on conditions and the circumstances.
PADI focuses on team diving. They also recommend that the team utilize the same gas mixes while conducting a dive—hard to argue against for obvious reasons—although PADI does not offer specific standard gas mixes like GUE (nor do other agencies). However, they do rely on standard gas switching protocols, in PADI parlance, the NO TOX gas switch (Note your tank label, Observe your depth, Turn on the valve, Orient the regulator hose, eXamine your teammates).
Divers are encouraged to always use checklists. Gas reserves are calculated using traditional thirds or “Rock Bottom” gas, the equivalent to GUE’s “minimum gas” i.e., the amount of gas required to get two divers back to usable gas, whether deco bottles or the surface. Divers are also able to use computers in gauge mode and tables or dive computers.
In Conclusion
Overall, I came away very impressed with the program and its focus on diver safety. But I wanted to get a perspective from someone who was familiar with PADI Tec as well as other agency programs. In this pursuit, I had the privilege of speaking with underground veteran Jim Wyatt, principal of Cave Dive Florida.
The ex-Navy diver is a former training director and instructor trainer for the National Speleological Society-Cave Diving Section (NSS-CDS) and a trimix instructor and cave instructor trainer for both IANTD and TDI. As far as his involvement with PADI, Wyatt is both a PADI course director and DSAT instructor trainer who has taught PADI Tec since 2002. Just the guy I wanted to talk with. “PADI Tec is a good program. They’ve made big changes and added trimix to their intro classes. I’d put their standards against anyone’s,” Wyatt, who’s hardly unbiased but likely knows the material as well or better than anyone outside the PADI organization, explained to me.
It is important to remember that all training agencies have standards; the critical question is, do their instructors follow them? After all, it is the instructors who are entrusted to provide training to students.
Without doubt, this is the work and challenge shared by all agencies, especially in the realm of technical diving. The challenge is even more complex for larger agencies like PADI and TDI, who have thousands of technical instructors. Managing and ensuring adherence to standards and quality instruction is undoubtedly a formiable task, even for smaller agencies like GUE, who have several hundred instructors.
Clearly, PADI bears the responsibility of ensuring that the quality of their Tec instruction matches the high quality of their standards and learning materials. I have no doubt that’s PADI’s goal and intent, and we wish them the utmost success in that endeavor.
Growing our cherished community with well-prepared, competent and capable technical divers, especially among the next generation who will eventually take the helm, is a shared responsibility, irregardless of the logo. With a shout out to GUE, we need to encourage and inspire each another, and our respective organizations, to strive for excellence in this regard! It’s all of “OUR” global community after all.
Special thanks to Asutay Akbayir, Eric Albinsson, Vikki Batten, Chris Brock, Samantha Pearson, Michael Richardson and Karl Shreeves for their help with my research for this story.
DIVE DEEPER
aquaCORPS archives: Put Another Diver In: John Cronin And The Business Of Marketing The Diving World (OCT 1995) I interviewed the late PADI CEO John Cronin in his office in 1995 just as the training juggernaut was rolling out its new Enriched Air Nitrox program. We talked about the founding of PADI, his vision of the diving business, the impact of tech diving on the market, PADI’s new enriched air nitrox courses, his thoughts on tech training and rebreathers, and where he believed the market was headed. Here is the original interview as seen in aquaCORPS. It ran as the cover story of aquaCORPS #12 Survivors OCT 1995.
InDEPTH: One Way The World Learns to Mermaid: The Mer-spective from PADI’s Karl Shreeves
Alert Diver.eu: Rapture of the Tech: Depth, Narcosis and Training Agencies
Michael Menduno/M2 is InDepth’s editor-in-chief and an award-winning journalist and technologist who has written about diving and diving technology for more than 30 years. He coined the term “technical diving.” His magazine “aquaCORPS: The Journal for Technical Diving” (1990-1996) helped usher tech diving into mainstream sports diving, and he produced the first tek.Conferences and Rebreather Forums 1.0 & 2.0. In addition to InDepth, Menduno serves as Senior Editor for DAN Europe’s Alert Diver magazine, a contributing editor for X-Ray mag, and writes for DeeperBlue.com. He is on the board of the Historical Diving Society (USA), and a member of the Rebreather Training Council.
Tren Maya is on the Wrong Track! An Update.
Doping for Depth
Hyperbaric Chambers Are Turning Away Divers. Will There Be One Nearby When You Need It?
Let There Be Mix!
Who You Gonna Call (in an Emergency)?
Über-deep with Cave Explorer Xavier Meniscus
Madagascar Madness
Why I Became a GUE Instructor
