Education
Urination Management Considerations for Women Technical Divers
Tech diver and doctoral student, Payal Razdan, offers an in-depth review of the options available to women tech divers for handling the call of nature.

By Payal S. Razdan
Header image by Rich Denmark
Proper hydration is an important element in the health and safety of athletes and sports enthusiasts. The ability to eliminate these fluids is equally essential in maintaining fluid balance and physical comfort. Appropriate physical protection is critical when diving for extended periods of time, both in colder temperatures and contaminated water. There are also times when professional and safety divers must remain suited when providing surface support. Drysuits offer the protection needed but require additional accessories in order to make it possible to stay in the suit for prolonged periods.
Traditionally, external urine collection systems (eg, adult diapers/nappies and external catheter systems) are used in settings when stopping or removing protective gear is not optimal. Understanding some of the anatomical and technical considerations needed to take care of this most basic physiological function may help divers select the right device for them and manage any potential complications that may arise.
Early Urine Management
What we now call ‘standard diving dress’ first evolved from ‘closed-dress’ (diver completely enclosed in helmet and flexible dress with hands exposed) during the 1830s. In the early 1840s, while working on the wreck of the Royal George off Portsmouth in Southern England, Augustus Siebe made gear modifications to meet divers’ needs and suggestions. This work eventually led to ‘standard-dress,’ but an option for external catheter systems did not follow until some 40 years later. In the 1930s, commercial diving systems initially held the urine in a catchment bag connected to a one-way overboard discharge valve that was opened once on the surface. Modernization eventually made it possible to void while immersed. These systems were incorporated into technical diving around the mid-90s, but were still designed exclusively for use by men.
According to Peter Dick, editor of the International Journal of Diving History, while some women were diving during the 19th century, it was not until the early 1930s that females began coming into the sport, some by way of diving their own homemade gear. It was not until after World War II that women began to take to sports diving in larger numbers. Equipment modifications eventually evolved to include women’s needs, albeit slowly. A female-friendly version of an external urine collection device was not available until the early 2000s. Until this point, women had been limited to either holding, self-catheterization, or nappies (adult diapers). For women divers, there are various types of external urine collection devices: portable urinals, female urination devices (FUD), nappies, and the external catheter systems; however, the latter two appear to predominate.

Divers preparing to go under the ice at Thetford Mines, Quebec. Shows that there is nowhere to go privately. Photo by Payal Razdan.
Nappy Know-How
Nappies were the original go-to device and remain commonplace in diving. Although they seem to be underappreciated, they are easy to don. While divers may choose to rely on store-bought brands there is an incredible, almost overwhelming, variety available online.
Nappy selection can be a science. Different brands allow for varying usable capacities up to an astounding 95 oz (2.8 L) with the Dry 24/7 Max AbsorbencyTM1. “While nappies may be preferred for shorter dives, it is about the right tool for the job” said Beatrice Rivoria, marine biologist and technical instructor with Zero Emissions who prefers nappies for short dives. Contrary to what some divers might believe, brands with max absorbency could be used for extended dive times. Additional features to consider are the wet thickness (how thick the product becomes at usable capacity), wicking distance, cost per brief, dimensions, and accessibility. Like with any diving equipment, it is best to try different options when possible. Some manufacturers and retailers are willing to send samples.
Nappies are available as either pull-on underwear style or tabbed briefs, the latter allowing you to slip out of and into a fresh nappy without the need to completely disrobe. This can be useful for instructors doing multiple dives per day, for individuals surrounded by ice and snow, for divers with no access to restrooms, for those where privacy is limited to sparse leafless bushes, and for those subjected to the buzzing gaze of a fellow diver’s drone. Women divers may also want to consider that perhaps different nappies may be needed for different types of diving.
The major downsides include possible leaks, discomfort, increasing bulk (when wet), skin irritation, increased risk of infection, and embarrassment. Also, depending on the type of nappy—tabbed or pull-up—they may present challenges between dives because of privacy issues. Nappies may not be the optimal choice for the environmentally conscious since they are not recyclable. Disposal during remote and/or expeditionary diving may also be inconvenient.
Leakage is generally a consequence of poor fit and/or inadequate absorbency. A healthy woman may experience a normal urge to urinate at approximately 300-400 ml and a strong need at about 400-600 ml.2 Even with the right fit, overflow can occur if the capacity of the product is inadequate for the diver’s urination needs and/or intended for light to moderate bladder leakage (e.g., such as during a sneeze) rather than sudden normal continuous flow. The risk for leaks is less likely with slow or intermittent streams, but the same could be said for all external urine collection devices. While nappies have both benefits and drawbacks, it is important to note that they may also be the only option for some divers who cannot use external catheter systems.
External Catheter Systems
External catheter systems have three main components: the external collection device (ECD), a catheter (tubing), and a discharge or relief valve (also called the P-valve), where the urine exits (Image). The ECD is the human-catheter interface that connects the external genitalia or pubic area to the catheter. For men, the ECD is a disposable sheath that fits over the penis like a condom with an opening at the tip to allow drainage. Condom catheters come in a surprising variety of different sizes, shapes, materials, and adhesive options (e.g., self-adhesive WideBand and Freedom) depending on the medical manufacturer. The ECD for women is a reusable one-size-fits-all elongated cup-like reservoir manufactured by either She-P (Fred Devos, co-owner of Zero Gravity Dive Center originally coined the name in 2007 after seeing a prototype), or SheWee Go.

The She-P reservoir is a handmade, medical grade, hypoallergenic silicone device encircled by a flat rim that is adhered to the skin using medical grade adhesive. The material is soft, allowing the shape to be altered somewhat by the user. The newest She-P version 3.0 has evolved to include slight concave modifications to the shape of the rim from the She-P Classic. The SheWee Go is a natural gum rubber device with a rounded ridge and is secured, rather than adhered, in place with three adjustable straps. Both male and female ECDs connect to a catheter allowing urine to flow toward the P-valve attached to the drysuit’s upper leg.

The P-valve is either balanced or unbalanced. The primary difference is that balanced valves remain open during the dive, allowing the pressure inside the catheter to equalize throughout the dive; whereas unbalanced valves remain closed (except for during urination). Unbalanced valves must also be primed (pre-dive urination) to remove the air space in the catheter. The urine passes through the tube, out the valve, and away from the body. Women are often advised to use balanced P-valves. It has also been suggested that the risk of complications with a P-valve may be less with a balanced valve.
According to informal online surveys on two Facebook groups (“Girls That Tech Dive” and “Cave Diving Mermaids”), a majority of participants stated that they used a She-P either alone or with backup leakage protection (e.g., nappy, an incontinence pad, or maxi pad). A review of various online retailers also seems to indicate that the She-P is more readily accessible. Alex Vassello from Custom Divers, and creator of the SheWee Go, admits that the only way to order a SheWee Go is through Custom Divers. He also feels that limited advertising and online resources may affect its visibility in the market, especially with new divers.

It is unclear whether accessibility and marketing strategies are influencing popularity or if it is the effectiveness and/or convenience of the devices. These two products have never been tested by a third party, so it is unclear how these two would compare in a dive-for-dive test. Although the She-P seems to be more common, both devices have individuals who prefer one to the other, and both have their benefits and challenges.
Vassello feels that one of the limitations of the SheWee Go is that it is less effective and more prone to leaks if used in a seated position. While Kristen Matlock has used a She-P for all terrain vehicle (ATV or side-by-side) racing in the past, she prefers a new disposable catheter system that has not hit the market yet. A number of women also mentioned that sitting in the She-P can be uncomfortable and most urinate either standing or in proper trim (horizontal body position) while diving.
The Decision to Opt-Out
Whichever ECD was preferred, women reported that they did not use it on every dive. Depending on the goal of the dive, location, dive profile, environmental conditions, personal tolerance, and the ECD itself, the urination challenges divers had to consider varied. Becky Kagan Schott, five-time Emmy award-winning underwater director of photography, technical instructor, and owner of Liquid Productions, says her strategy involves planning dives to be short enough to eliminate the need to rely on anything, or nappies at most. “If I think the dive will run over 3 hours, or I’ll be suited up that long, I’ll decide on the diaper or She-P depending on where I’m diving,” Schott said. While she prefers to not use anything, she knows that is not always possible.
Each diver’s pre-dive urine ritual when diving without an ECD is as unique as the diver. Like many women, Lyzz Rooney, an instructor with UnderH2O and an operating room RN in Portland, urinates immediately before donning her suit if she is not applying the ECD. However, location matters, and she always dons the She-P for boat dives. “I can’t take my clothes off and dangle my bits off the side without embarrassment,” Rooney joked. Lauren Fanning, GUE instructor and marketing manager at Halcyon Diving Systems, uses her She-P for longer dives, no matter the location. But Fanning still makes sure she is appropriately hydrated and employs a ‘rule of three’ before getting into the water, urinating at least three times before the dive to ensure she can manage. She also emphasized that the ECD is an important piece of equipment for technical diving and that she “wouldn’t go into the water without a breathing device…[or] without the ability to urinate during a long dive.”

Female divers were more inclined to don ECDs on longer dives or when breaks between dives were considered too short. Long dives were defined by the length of time one could wait without having to urinate (the threshold) and the decompression obligation that would be incurred. According to survey participants, the threshold ranged from approximately 90 minutes to four hours. Good urination management is especially critical since divers may want to rest on the surface following decompression diving in order to off-gas before exiting and/or lifting heavy equipment. “When I’m teaching, most of the time I don’t bother with a [She-P],” explained Marissa Eckert, a tech and rebreather instructor and co-owner at Hidden Worlds Diving. However, “I’ve done 11-hour cave dives; a diaper will not stand up that long.” Rooney, on the other hand, who has been using a She-P for about 10 years, said, “I hook up every day of instruction since I know I’ll be in a suit for six or more hours.”
Nathalie Lasselin, cinematographer and explorer, spent two 15-hour days diving 70 km (43 mi) of the Saint Lawrence River in Québec. The Urban Water Odyssey, to bring awareness regarding water quality in Québec, involved over a year of planning, multiple sponsors, and a multi-member support team. A leak could have put an end to her carefully planned dive. After considering her options, she chose to dive with a She-P and backup. While she considered using an internally placed catheter, she was concerned about a catheter system failure, retrograde flow, and direct inoculation by cold, bacteria-filled river water.

Lasselin faced another challenge when the back of the device became unglued, a common issue experienced by She-P Classic users. Lasselin was also using a diver propulsion vehicle (DPV) attached to a crotch strap, which meant the strap was applying “constant friction and tension at the wrong place.” Laura James, the North American representative for She-P, stated that “tight harness waist belt/crotch strap combos…can contribute to success or failure rate.” Lasselin admits that the She-P did not work 100%, but it was the only option she felt she had. Her strategy also included adding various layers including two thongs (on each side of the She-P), a nappy, and latex underwear to secure the She-P and to contain leaks.
Extended dive times (e.g., dives greater than five hours) are likely to be beyond a diver’s threshold. Divers were also less inclined to withhold fluid intake in order to lower urine output prior to performing dives with decompression obligations. The primary concern reported was the potential impact that dehydration may have on the risk of decompression sickness. “Much of diving is about risk (uncertainty) management,” states Gareth Lock, owner, trainer and coach at Human in the System Consulting/The Human Diver. Lock feels that “divers try to limit their DCS risk by being correctly hydrated, and the use of an external catheter system allows that to be managed relatively well in male divers. Despite this, there are numerous stories of male divers not having a urination system and not hydrating properly as a consequence. For female divers, the solutions afforded to them are not the same.”
Nappies on their own “have limitations, especially for protracted and/or decompression dives,” said Nelly Williams, technical diver and co-owner of XOC-Ha in Yucatan, Mexico. Williams opts for the P-valve on longer dives “where proper hydration is essential.” Consequently, extended dive times and/or prolonged decompression might result in greater urine output. The increased output may be problematic if a low capacity nappy is used because the volume produced might be more than it can absorb. This could potentially lead to leaks or expose the skin to urine for a prolonged period of time.
To She-P or She-Wee?
According to Deborah Johnston, cave explorer with the Sydney University Speleological Society, motivation to use her She-P was dependent upon finding a balance between the perceived challenges and the benefits of being able to urinate during the dive. The decision to ditch or don the She-P was generally based on whether the dive time was long enough to tolerate the challenging site preparation and cleanup. She-P proper site preparation requires hair removal, removal of oil and moisture from the skin, application of an adhesive, and proper placement of the device. This still does not guarantee a leak-free dive, and the ECD or P-valve may still fail which may present a thermal risk to the diver. A majority of survey participants reported leaks, primarily from the perineum (backside). Although women used back up protection to manage leaks, they also expressed discontent with the need for the backup and the extra waste is created. Cleanup refers to the removal of adhesive residue and cleaning and storage of the ECD. “Cleaning up adhesive afterwards is my biggest complaint with a She-P,” Fanning admitted. Her frustration with the aftercare and adhesive cleanup is mirrored by many women.

Lyzz Rooney trying to use her female urination device with a drysuit in between students open water certification dives. Photo by Jonathan Fletcher.
Ease of use and good fit were the primary reasons cinematographer and explorer Jill Heinerth has been a SheWee Go user for over six years. While she admits there is no perfect solution, she “has had better luck with the SheWee Go and feels more comfortable” with it. Heinerth also admitted that site preparation and the need to glue the She-P in place seems particularly impractical in expeditionary diving. Indeed, women reported that frustration with site preparation and cleanup, poor device fit, and the likelihood of experiencing a leak were deciding factors for choosing the SheWee Go or nappies.
Availability can also be an issue. Gemma Thomas, an instructor located in Singapore, reported that the medical adhesive needed for the She-P was not available in that country. In addition, mature women may experience vulvovaginal atrophy as estrogen levels decline. Symptoms may include thinner, less elastic, and drier vulvar and vaginal tissues4. Changes may also occur following hormonal therapy which also makes the SheWee Go or nappies a potentially good option for some, since removing the device may lead to abrasions or tearing. One diver, who will remain anonymous, said that for her nappies were the only solution following estrogen reduction treatment for breast cancer.
Challenges and complications
Ideally, an effective ECD should be easy to apply and use, should perform without leaking, and should keep the skin reasonably dry. A device that is simple to maintain is a plus. Most importantly, ECDs should function without causing discomfort or injury. Unfortunately, the perfect option currently does not exist. Application and leaking seem to be the greatest sources of frustration with the external catheter ECD systems, although this is hardly an issue for women only. A 2010 survey of (predominantly male) pilots flying for the U.S. Air Force U-2 Reconnaissance Squadrons reported that 60% of individuals had problems with their ECDs including poor fit, leaking, and skin damage from extended contact with urine.5 Rooney added that while she has had leaks and P-valve failures, “the boys have had their fair share of both leaks and catastrophic failures [and] have their own trust issues with their systems too.”
That women suffer from poor fit and leakage should come as no surprise given the variation in female genital anatomy and the one-size-fits-all approach of ECDs. A quick review of biomedical literature available through PubMed returns measurements for normal female genital variation based on various factors including race, age, weight, and hormonal changes. Wendy Grossman, who has been cave diving for over 16 years, feels that not everyone understands that “not all vaginas are made equal.” Grossman wore a She-P for about 10 years before deciding to use nappies exclusively.
It seems that female anatomical variation may be underappreciated or perhaps under-recognized by ECD producers and female consumers alike. In fact, the lack of appreciation even inspired Jamie McCartney’s 2011 wall sculpture “The Great Wall of Vagina,” a 10-panelled wall sculpture comprised of the plaster casts of genitals from 400 female volunteers. Both Vassello, creator of the SheWee Go, and Heleen DeGraw, creator of the She-P, do feel that human error plays a role in failure rates. While leakage may be due to poor adhesion caused by improper area preparation, equipment interfering with the seal, and with general challenges placing the device, the real challenge may just be that one size does not fit all.


Other concerns reported with She-P use include skin irritation/burning caused by the adhesive, which are typically due to contact between the glue and freshly shaved/waxed skin. Rooney found that “on really long days with multiple dives, I’m prone to more leaks.” Women reported discomfort from having to sit on the ECD during surface intervals. Cases of catheter squeeze, urinary tract infections, and pneumaturia has also been reported with P-valve use in both men and women.3 According to personal reports, catheter squeezes were due to accidental closure of a specific type of P-valve (balanced valve) or deliberate closure in response to a leak prior to ascent. In these cases, the pain was accompanied by bruising.
Final considerations
While external systems provide the convenience of being able to urinate without disrobing, divers must consider the unique challenges associated with their environment. Immersion, pressure changes, and equipment restrictions can contribute to complications, particularly for women. Effective urination solutions are important not only for comfort but for functional and safety reasons as well. Divers ready to consider using an external urine collection device should talk to other divers, review available resources, and consider the possible tips and tricks available.
Tips for New Divers
- Don’t be afraid to ask questions; it may be an uncomfortable subject for some, but one that women should be free to discuss.
- Know your body: pay attention to your fluid intake, urination needs, and how environmental conditions impact your threshold.
- Test your preferred external urine collection device in the shower before your dive and perhaps take it for a dry test run.
- Choose the right tool for the job: make sure your nappy is the right size and has the correct capacity for the dive.
- Consider adding cleansing wipes to your tool kit: use them prior to She-P placement to remove oils from the skin or after to remove adhesive residue. Wipes are also useful for managing any accidents.
- Give yourself enough time to prep for She-P placement and to allow the glue to adhere properly.
- Perform a pre-dive system test: once you have donned your gear, ensure your P-valve system is functioning prior to entering the water.
- Adjust volume control: fully relaxing may cause the ECD cup to fill too fast creating some back pressure, possibly leading to leaks.
Footnotes/References
1. XPMedical [Internet]. Adult diaper reviews; [cited 2019 July 16]; [about 3 screens].
4. Marnach ML, Torgerson RR. Vulvovaginal Issues in Mature Women. Mayo Clin Proc. 2017; 92(3): 449-54.
5. Von Thesling GH, Coffman CB, Hundemer GL, Stuart RP. In-flight urine collection device: efficacy, maintenance, and complications in U-2 pilots. Aviat Space Environ Med. 2011; 82(2): 116-22.

Payal is a doctoral student in kinesiology at Université Laval exploring the impact of extreme environments on physiological adaptation, human performance, and health and safety. She is also a certified technical and cave diver. Her background in public health education and training as an Emergency Medical Technician guide her efforts to develop communication, outreach, and education products that use physiological concepts to improve diving safety.
Dive Deeper:
“The Divine Secrets of the She-P Sisterhood” by Michael Menduno (DIVER August, 2010)
Divine Secrets of the She-P Sisterhood, Episode 1: “What’s In the Kit?”
Divine Secrets of the She-P Sisterhood, Episode 2 Part 1
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.