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Tom Mount (1939-2022) Brought Considerable Depth and Experience to Technical Diving

Though most tech divers have heard of Tom Mount and the International Association of Nitrox and Technical Divers (IANTD), it’s likely only a few insiders know his back story and about the considerable depth and experience he brought to what would become known as technical diving. Here author and Asian tech pioneer, Simon Pridmore takes us on a deep dive into Mount’s many achievements. May he rest in peace.



By Simon Pridmore. Header image, “The old warhorse —Tom Mount post-dive 1993 Ginnie Springs. Photo by Kevin Denlay

In January, when the news emerged of Tom Mount’s death, Facebook lit up with hundreds of messages from right across the acquaintance spectrum. Some were from close friends who had known Tom for many years; others were from people he had only met briefly or quite recently. Some comments even began with the words, “Although I never got to meet Tom…” and then went on to express their sadness at his passing.

Courtesy aquaCORPS archives

Condolences poured in from all over the world, not only from Florida and elsewhere in the USA, but also from Central America, the UK, Europe, Southeast Asia, China, Australia, New Zealand, Micronesia, pretty much everywhere people scuba dive. Many were from countries Tom never visited, written in languages he didn’t speak.

He was 82 when he died. If in 1989, you told the then 50-year-old Tom Mount that his death would send a minor tremor right around the diving world, he would have been astonished. Up to that point, he had achieved a great deal, but he was little known outside America. Within a few years, his fame would be global.

How did this happen? 

As is often the case, to understand why the path winds the way it does, you have to go back and follow it from the start.


Tom was born Warren Thomas Mount in 1939. He learned to box when he was nine years old and thus began a lifelong passion for martial arts, which would both keep him fit into his older years and provide much of the philosophy behind his approach to scuba diving.

The US Navy taught him to dive. He joined up in 1957 and became a Navy diver. He was also attached for a time to the Army Corps of Engineers and was primary author of the Army Corps of Engineers (Diving) Course Syllabus.

Mount getting ready to splash. Photo by Bret Gilliam


The Navy used both open circuit and closed circuit apparatus. Navy divers were introduced to the aqualung by its co-creator Emile Gagnan in early 1949 and, during Tom’s time, the rebreather units they deployed included the Draeger LT Lund II and the Emerson – Lambertsen UBA.

In the 1990s and beyond, Tom would subsequently become a passionate advocate for the use of rebreathers in sport diving. Inventors and manufacturers would beat a path to his door, seeking his advice. Dive Rite’s Lamar Hires was one of the beneficiaries. 

“We visited him in Miami and Jared and I went out on his boat. Tom and I took two units down to about 18m/60 f and tested them. I was new to rebreathers and needed his guidance on the design. He was very impressed with it but, more importantly, I got a one-on-one lesson about loop volume and trim. I remember watching Tom pull off weight because he was heavy and I proceeded to do the same thing. The discussions that followed helped shape the product.”

Mixed Gas 

After leaving the Navy, Tom went to work as diving officer for Lockheed at Cape Kennedy (Canaveral), the base for NASA’s space program. 

In 1967, he took up a position as director of the Scientific Diving Program (SDP) at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science (RSMAS). The school’s website recounts how, under Tom’s direction:

“The SDP introduced mixed gas diving to RSMAS scientists.”

ANDI and IANTD agreeing on blending standards at the Tek.93 Conference. Photo courtesy of aquaCORPS archives.

He ran the program from 1968 to 1976, when he left to spend two years with the YMCA as its national scuba programme training director. 

During this time, however, Tom often had matters other than work on his mind.

Going Underground

Just before leaving the Navy, he discovered cave diving. His first introduction was at Zuber Sink, northwest of Ocala, Florida, later to be acquired by Hal Watts and renamed as Hal’s Forty Fathom Grotto. Watts and Tom first met around this time and were to stay firm friends to the end. 

Tom referred to these early days in a 1995 aquaCORPS magazine interview

“I started deep diving when I got out of the Navy in 1962 and I thought I was a real pioneer. I was shocked to find that people were (already) getting into the Andrea Doria and working at 250, 260 feet in caves.”

By 1963, both Watts and Tom were training cave divers and doing deep cave dives. Tom teamed up with Frank Martz to bottom out Zuber Sink at 240ft (hence “Forty Fathom”) and explore the hitherto unvisited depths of Lost Sink, later to become better known as Eagle’s Nest. In 1965, Tom and Martz set the world record for the deepest scuba dive on air with a descent to 110 m/360 ft, a record that stood until Watts and A.J. Muns dived to 120 m/390 ft two years later. 

They were at the pinnacle of their sport. In 1966, Sheck Exley, a man who was later to become one of the deep cave diving elite himself, did his first cave dive. Writing in 1984 and harking back to his very early days, Exley wrote:

“Now, for better or for worse, my life was set. Sports heroes…were now replaced by Mount, Watts, Harper on the list of people I most admired. Hal Watts was the best deep cave diver, Tom Mount had the most cave dives and was the best published and John Harper was simply the best, period.”

Tech pioneers L2R: Tom Mount , Bret Gilliam , Rob Palmer and Richard Bull in Florida 1992. Photo courtesy of Bret Gilliam


In the late 1960s, Lithuanian Dr. George Benjamin became fascinated by the Blue Holes of Andros in the Bahamas and started diving in them. Long on enthusiasm but short on experience, as he began to explore deeper, Benjamin decided he needed help and invited Tom to come over from Florida to join him. Tom recruited other top Florida cave divers to form a team to push the cave system deeper and further. These included Martz, Tom’s then wife Zidi Goldstein, Ike Ikehara, Jim Lockwood, Sharee Pepper, and Dick Williams. 

In early 1971, Tom and Martz found a new tunnel with a restriction at 85 m/280 t. When the team returned in September of the same year, Martz was determined to try to go beyond the restriction. Benjamin was against the idea. He thought it was dangerous and conflicted with his plans. And he was paying the bills. Tom told Martz that the project was their priority, but Martz was insistent and eventually Tom persuaded Benjamin to allow the dive to go ahead. 

It was a story Tom would often tell.

“Frank died on a dive in Benjamin’s Cave in Andros Blue Hole 4 in the Bahamas on September 4, 1971. Frank and Jim Lockwood were going to explore a passage Frank had found on our last trip there. Zidi and I were to add line in the other passage. Prior to the dive I had a premonition one of us would have an accident. Normally I listen to my intuition, but on this dive I did not. Frank and I had argued earlier…so I thought my bad feeling was over our disagreement.

But I did continue to have the feeling as the dive started. About 25 minutes into the dive, I felt someone had died. It was not Zidi or me, and as we exited we saw Jim. Jim and Frank had got into a bad silt out and Jim felt Frank had passed him, so expected to see him on the way out. Zidi went up to decompress and Jim and I doubled back to try and find Frank. We pushed our air to the maximum and returned to decompress on oxygen.”

To this day, Martz’s body has not been found.

The subsequent police investigation report quotes Tom as saying:

“Frank Martz was probably one of the best cave divers in the world…He was one of my best friends and one of the people you think it is impossible for them to die diving. He has done more to develop safe cave diving equipment than anyone and the cave diving world will miss him…” 

Tom always cited Martz’s death as a turning point. You can just feel his disbelief in his police statement. Subsequently, he and others came up with a variety of wild theories to explain how Frank had died. The possibility that he had just got something wrong was too hard to process.

Like other technical diving pioneers, the experience of losing a close friend to the sport would act as a driving force.

Tom Mount and Gary L. Taylor mixing on Elm Street. Photo courtesy of Gary L. Taylor.

In his book, Technical Diving from the Bottom Up, Kevin Gurr recalls:

“In the water, (Tom) was, and still is, a task master. I’d never heard anyone scream underwater before. You knew when you’d screwed up.”

That was Tom’s style. He could be absolutely terrifying; chewing you out in the darkness, half a mile into a cave, when you made a mistake. But behind the unintelligible bellowing was the message:

“My best friend, the best cave diver I knew, made a mistake and died in a cave. If it happened to him, it can happen to you and it will happen to you if you don’t focus constantly. Never again! Not on my watch!”


A few years earlier, together with Watts and others, Tom had already been involved in measures to improve safety standards in cave diving. The increasing interest and participation in the sport in the 1960s had led to a number of diver deaths, which in turn led to bad press and political pressure on land owners to close off access to the caves; even threats to ban cave diving altogether. 

Photo courtesy of Gary L. Taylor

In response, the USA’s first cave diving organization, The National Association of Cave Divers (NACD) was established to offer courses and certification in cavern and cave diving with the goal of improving safety. Those who assembled in Gainesville, Florida, on May 21, 1969, to sign the articles of incorporation were Tom Mount, Hal Watts, Dale Malloy, David Desautels, Lawrence Briel, Ronald Wahl, James Sweeney, and Gilbert Milner. 

Tom was NACD training director and, after Martz’s death, wrote The Cave Diving Manual (1972), one of the first US cave diver textbooks (the very first was Exley’s Dixie Cavern Kings Cave Diving Manual (1969). Subsequently, Tom was lead author on Safe Cave Diving (1973), to which Exley also contributed.

In terms of his speaking voice, Tom was far from a perfect communicator, especially if you were not a native English speaker, his drawl and soft speaking voice making it difficult to pick up what he was saying.

Fortunately, over the years, he wrote it all down. The cave manuals were followed by Practical Diving: A Complete Manual for Compressed Air Divers (1975), written with Ikehara and published by the University of Miami.

Many more books would follow.

Photo by Kevin Denlay.


Survival was a common theme in his teaching and writing. He would frequently tell the story of an air sharing exit when he and a fellow diver both ran out of air a long way before the end of the cave, yet kept pushing on, finning regularly, not panicking, knowing that it was the only way they could survive. Two mantras that his students would hear time and again were:

“Only you can breathe for you, only you can swim for you, only you can think for you” 

“Survival is making the choice to continue and not quitting regardless of the odds.”

One DEMA Show, Tom was receiving an award in front of a large crowd and, in the front row, he spotted Don Shirley, one of South Africa’s top cave divers. Calling him up on stage, Tom told the story of how Shirley had survived an eight-hour ascent from a deep cave while suffering from devastating, crippling decompression sickness. Pointing to Shirley, Tom announced:

“This is the guy who deserves an award. He is a true hero. He survived when it would have been easier not to.”


Mindfulness, a concept borrowed from his martial arts training and his PhD studies, was another standout feature of Tom’s training technique. In his description of the circumstances leading up to Martz’s death (above), he talks about premonition and intuition. Tom saw developing awareness of these phenomena, and listening to your feelings as important components of a survival mentality. The course materials he developed also included advice for divers of the value of pre-dive visualisation and post-dive reflection.

Nowadays, technical diver training has come to accommodate all these aspects, but when Tom first introduced them they were radical and innovative. Divers being divers, they generated a certain amount of cynicism and Tom was dubbed Obi-Wan Kenobi (although not within earshot). During a course, divers would dread the meditation session at the end of a long day of caves and classes. The urge to fall asleep was almost impossible to resist. Nobody wanted to be the first to shatter the peace with a loud snore!

Tom Mount pre-visualizing a dive at Ginnie Springs. Photo courtesy of Kevin Denlay

Tom saw introducing mindfulness to extreme scuba divers as one of the most significant elements of his legacy. In his TekDive USA 2016 speaker biography he wrote:

“…our primary strengths lie in the ability to use intuition and our use of Chi. (I consider) three elements of Survival and Existence to be the key to life.”

Turning Point

During the 1980s, Tom wrote travel guides, took underwater photographs, and submitted articles for dive magazines. Together with Patti Schaeffer, who was to become his wife and business partner for the next two decades, he even published A Guide to Underwater Modeling (1983).

Tom’s author biography in this book gives a good idea of the scope of what he was doing around this period. He was running International Diving and Marine Consulting out of his Miami Shores home and was Marketing VP at Teach Tour Dive. He was also heavily involved with National Oceanic and Atmospheric Administration (NOAA) – the maritime equivalent of National Air And Space Administration (NASA) – as an aquanaut, a saturation diver and a contributor to both the NOAA Diving Manual and the NOAA diving programs, for which he received an award.

His life was about to undergo a radical change. When NOAA Deputy Diving Coordinator Dick Rutkowski retired in 1985, he formed the International Association of Nitrox Divers (IAND) and began to teach sport divers how to blend and use nitrox, which, up to that time, had been used extensively by the scientific and military diving communities, but ignored by the sport diving world. Rutkowski also linked up with Ed Betts in New York to start American Nitrox Divers Incorporated (ANDI). 

IANTD advert in aquaCORPS Journal

Having written the first nitrox diver training manual and workbook in 1989, the following year, Rutkowski sold IAND to Tom, although he remained on the Board of Directors.

In the USA in the late 1980s, the activities of various groups of divers who were involved in diving beyond the conventional limits began to gain more prominence. The groups started to coalesce and exchange ideas. Nitrox was part of this conversation, along with deep wreck diving, cave diving, diving on helium-based gases, oxygen decompression, and using rebreathers. A wave was building. 

Michael Menduno’s aquaCORPS Journal was the first magazine to focus entirely on what was going on in “beyond-limits” scuba diving and was highly influential in bringing the tribes together. In the January 1991 issue of aquaCORPS, Menduno trialed the phrase “technical diving” as a catch-all term for these activities.

He wasn’t the only one to find this an apt description. Tom took note and added the word “Technical” to the name of his newly acquired training agency, so it became IANTD. 

Just as in the late 1960s, when there had been no training agency offering formal education and certification for people who wanted to dive in caves, similarly, when the 90s began, no organisation existed that offered the same for aspiring technical divers. As with cave diving, from a safety and liability point of view, there was an obvious need.

If you had wanted to design an individual to start such an organisation, you couldn’t have done much better than Tom Mount. If he hadn’t existed, someone would have had to invent him. He had a background in building diver training agencies and writing textbooks, he had been diving with rebreathers since the 1950s, deep diving since the 1960s, and working with mixed gas since the 1970s. He also had prestige and status among extreme scuba divers – in 1995, aquaCORPS dubbed him a “gray-beard” of cave diving. (Tom was 56! Already an ancient seer from Menduno’s comparatively youthful perspective.)

One of the first books on mixed gas scuba diving. Published in 1992

Not only could Tom ride this wave, he could get ahead of it and be one of the leaders of the new movement. He added new members to his Board of Directors who would fill in some of the gaps in his skillset and access. IANTD may have been a band in which he could play all the instruments, but he was not a natural lead singer.

The two people he chose fit the bill perfectly: The first, Bret Gilliam, was someone Tom had known since his Andros days. Gilliam was a serial successful entrepreneur with a wide network of contacts, a gift for marketing, and a deep diver who had just set a new world record for deep air diving. Gilliam thought:

“Tom was one of the most skilled divers I had ever met, and we had so much in common.”

In 1992, Gilliam would publish a book called Deep Diving through Ken Loyst at Watersport Publishing and he and Tom would team up to write Mixed Gas Diving for Loyst the following year. These were the first technical diving textbooks, and both became worldwide bestsellers.

The second recruit was Capt. Billy Deans, who had developed mixed gas diving procedures in Key West, Florida, and had been introducing deep wreck divers in the US Northeast to his systems. 

Gilliam and Deans were both charismatic figures with front-of-house personalities, big reputations, and connections to parts of the technical diving world beyond the Florida caves – just what Tom needed.

The first three IANTD trained Open Water Diver Instructors – 14th May 1993 – with Instructor Trainer Tom Mount and two assistant instructor Rottweilers. Photo by K. Denlay

His next task was to develop standards, procedures, and teaching materials for a mixed gas and planned decompression diving training program that could both stand on its own and bolt on to the existing sport diving education pyramid. Tom was in familiar territory. After all, he had already authored training programs for groups as varied as Navy and Army divers, scientists, cave divers and the YMCA. 

The entry point was the nitrox diver course, introducing divers to gases other than air. The next step was planned decompression dives; then dives using multiple gas mixes. With each subsequent level dives became deeper and longer. 

The top step on the pyramid was trimix diving; that is, diving with a helium-based bottom gas, a travel / first decompression gas and a final oxygen rich decompression gas. This course would certify sport divers to explore depths to 300ft. As Tom told Menduno in his 1995 aquaCORPS interview, it was not something they entered into lightly.

“We had a lot of concerns about trimix when we got started. In fact, Billy [Deans] and I, and a bunch of other people, talked about it for two years. “Do we really want to take the responsibility of certifying somebody as a trimix diver?” There was a lot of trimix teaching going on, but no one had actually said, “You are a certified trimix diver.”
Remember, there was no insurance for this stuff in those days; it didn’t exist. Eventually, we went ahead and developed training programs and standards.”

One of Deans’ early trimix students in the precertification days was author, journalist, and pioneer deep wreck diver Cathie Cush. She remembers that she was one of a select few.

“Billy Deans said that only about 20 divers did his trimix program in 1991, and he had another 20 at a single program in New Jersey in spring of 1992. Of course we wanted to go deeper, stay longer, be safer… And we knew we were pushing it with deep air. We just had to figure out how to do mix in scuba tanks instead of with hoses.”

The technical training pyramid Tom designed became the template that every major sport diver training organisation would follow as they all eventually developed their own technical diving programs.

Tom Mount and author Simon Pridmore with trimix students in Thailand in 1997.”

Magic Beans

Although the word had been in the company name from the beginning, IAND / IANTD had not been very international in its early years. In 1991, that was all about to change.

Word spread beyond US shores that Tom and Co. had the magic beans, and people from all over the world climbed up the beanstalk to Florida. The English speakers came first; the Brits in the vanguard, followed by the Australians. As Kevin Gurr remembers, when he, Richard Bull and Rob Palmer arrived to learn the secrets of mixed gas diving:

“You were taught in Tom’s house and often ended up sleeping with one or two Rottweilers after a long day’s diving. The only text was Dick Rutkowski’s Nitrox Diver; everything else you learned by example… On land the lectures often took the form of open discussion because we were all learning.”

The Brits were planning to start their own pan-European technical diving agency, but in the end Gurr became the first overseas IANTD licensee. Others were to follow: today there are 23 international IANTD licensees covering the entire globe. In the field of scuba diving, this was a groundbreaking business model.

It was also a pain in the neck. From running a small local company, Tom suddenly found himself at the head of a global empire, fighting fires on four continents, trying to maintain quality control among those who came and signed a contract that empowered them to rule their own faraway IANTD kingdom in his name. 

Some were worthy acolytes: others proved not to be as reliable as hoped. Selecting the right individuals was very difficult. After all, how can you assess a person’s character and potential on the basis of a relatively brief acquaintance and when you know nothing about them beyond what they have told you themselves? In those days, you couldn’t just Google someone. 

Tom decided to judge people by what he could see for himself – how they dived, how they dealt with the cave, and how they understood his ethos. You would not graduate and become part of the IANTD system until you had been “Mounted”, as some called it. Tom would organise huge international gatherings in Lake City, roping in trusted cave instructors, like Larry Green and John Orlowski, to help run the training. 

Mostly this technique was successful. Sometimes it wasn’t. Some of the folks who came and took away the magic beans had personal agendas and had to be disciplined, although this was often hard to do at a distance, even with online communications in a flattening world. The mountain is high and the king is far away, as the Chinese say.

The arrival of the Internet meant Tom didn’t have to fly off to other parts of the USA or foreign lands to respond to criticism, deliver rebukes or demand change; he could fly off the handle on an email or in a chat room instead. He never pulled a punch, and some of his exchanges were legendary in their fury. People who had only met polite, smiling, soft spoken Tom in his land-based life were surprised. Anyone who had ever been on the receiving end of Tom’s reaction when they did something wrong in a cave was not surprised at all. 

While Tom was teaching disciples, building a network, fighting online battles, wrestling technical diving into manageable shape, and making sure his training programs had legal footing, he had a solid team behind him in the office, led by Patti, son David, and Don Townsend.

By 1995, Menduno, writing in aquaCORPS, summed up the state of play thus:

“It wasn’t too long ago that technical diving was regarded as the lunatic fringe of sport diving… “You’re going to do what?”
Enter Tom Mount. In less that five years, the 56 year-old former U.S. Navy diver… and one of the graybeards of the NACD… has built the world’s largest technical diving agency, pulling together the lion’s share of the “big names’ in more than a dozen countries under the IANTD banner. Considering the egos involved – no small feat indeed.
Under Mount’s leadership, IANTD has created a structured series of technical diving courses and training standards, has nailed down an insurance program providing coverage at depth and spun off at least one other agency.” 

This “spun off” agency was Technical Diving International (TDI), established in 1994 by Bret Gilliam and Mitch Skaggs. It too would come to span the world. 

Graybeards are we? Tom Mount and Michael Menduno at TEKDive USA 2018. Photo courtesy of M. Menduno


Industry acceptance of technical diving—something Tom and others had fought hard for—was cemented in the late 1990s, when the mass-market training agencies expanded their range to include nitrox and technical diving, but this victory brought its own challenges. IANTD, TDI and ANDI no longer held a monopoly. Nevertheless, the IANTD empire continued to grow, especially overseas. In the beginning, of course, the USA had been the most successful office in terms of certification numbers. A few years later, it was Central Europe. Then it was Korea. The fulcrum of scuba diving was moving east and the licensee business model meant that IANTD was there already. Another consequence of the expansion was that Tom started travelling further afield to run courses in places such as Pattaya, Thailand and Bikini Atoll in the Marshall Islands.

Deans eventually hung up his fins, and US Navy Commander Joe Dituri came on board as a director. In 1998, Tom published the Technical Diving Encyclopaedia, which would become the seminal text for a new generation of advanced divers, just as Mixed Gas Diving had been for their predecessors.

In 2000, the Academy of Underwater Arts and Sciences honored Tom with a NOGI award for Sports Education. Movie director and fellow NOGI awardee James Cameron described getting a NOGI as “the underwater equivalent of winning an Oscar except a lot harder!” 

In 2005, after a hectic 15 years at the helm of IANTD, retirement seemed to be in the cards, as the company was sold, only for the deal to fall through in traumatic  fashion. Dituri, the international licensees and old friends kept the wagon rolling and Tom eventually returned to pick up the reins. It was not until 2015, when Luis Augusto Pedro came on board as COO, that Tom could move out of the front line and spend more time with wife Gexa. 

Nevertheless, he remained CEO and figurehead, he was still often spotted wading into the ocean with a new rebreather model on his back and he was still writing until well into his seventies.”The titles of the Tao of Survival Underwater (2008) and the Tao of Cave Diving Survival (2016) show how, over 50 years, the times might have changed, but the basic themes and messages remained the same.

By now, he could genuinely enjoy being a “gray-beard,” accepting further awards and speaking invitations and, as his Facebook page shows, attending events and meetings and befriending yet another crop of technical divers – the only difference being that this new generation demanded selfies.

Tom Mount RIP.

Photo courtesy of the aquaCORPS archives


Tom was never one to blow his own trumpet. He did not write an autobiography, rarely agreed to interviews and, when asked to supply an author or speaker biography, usually did no more than list his awards and accomplishments. This piece has been compiled from a host of sources, including personal memories, recollections of conversations with Tom over the years, input from some of Tom’s friends and colleagues, and details of Tom’s life and opinions gleaned from books and the few interviews he did give. 

Additional resources:

Facebook: Tom Mount

Wikipedia: Tom Mount

IANTD: Training with Tom Mount Classes (Wayback Machine 1997)

PSAI: Tom Mount and PSAI 

IANTD: The Early Evolution of Technical Diving – Overview

aquaCORPS: You’ve Come A Long Way Baby: Tom Mount Talks Tech by Michael Menduno (1995) Deep Diving: An Advanced Guide to Physiology, Procedures and Systems, by Bret Gilliam, Robert Von Maier, John Crea Mixed Gas Diving: The Ultimate Challenge for Technical Diving by Tom Mount, Bret Gilliam et al Technical Diving from the Bottom Up, by Kevin Gurr

Divernet: THE TECHNICAL DIVING REVOLUTION – PART 2 by Michael Menduno (2019)

Simon Pridmore was a pioneer of technical diving in Asia. Today, he is one of diving’s most prolific writers, with a five volume Scuba series, several guides for travelling divers, a biography and even a couple of divers’ cookbooks to his name. He is currently working on a new book called Technically Speaking, a collection of talks about technical diving, including the history of tech, what went before, how it came about and why things developed the way they did. Learn more about Simon and his books on his website or via his Scuba Conversational newsletter.



Located high in the Sierra Mazateca mountains in Oaxaca, Mexico, Sistema Huautla has captured the imagination of elite cave explorers for more than 50 years. Join photographer SJ Alice Bennett and cave/tech instructor Jon Kieren on Beyond The Sump’s recent March/April 2022 expedition to Sump 9.




Text by Jon Kieren. Images by SJ Alice Bennett.

🎶🎶 Pre-dive Clicklist: 붐바야 (BOOMBAYAH) by BLACKPINK curated by Steve Lambert

Sistema Huautla, in Oaxaca, Mexico, one of the most iconic and expansive cave systems in the world with over 30 entrances, more than 100.7 kilometers/62.5 miles of known passage, and reaching a depth of over 1500 meters/5000 feet, has been an obsession for cavers around the world for over 50 years. Every year, several groups such as Beyond the Sump (BtS) and Proyecto Espeleológico Sistema Huautla (PESH) mount expeditions to the region to explore. Surrounded by karst topography with several other gigantic systems, such as Chevé and Kijahe Xontjo are close by, there is surprisingly only one main exit point for the water flow (based on several dye trace studies), the Huautla Resurgence. Huautla is still being actively explored from the plateau to find the allusive connection with its resurgence. Terminating in a 9th sump at 81 m/264 ft depth, it is logistically extremely difficult to push the end of the line from there. This leaves exploration from the resurgence as the most likely tactic to make the connection.

Santa Ana Cuauhtémoc.

Nestled deep in a canyon 1200 m/4000 feet below the sleepy little town of Santa Ana Cuauhtémoc in the Sierra Madre de Oaxaca mountains in Oaxaca, Mexico, is the Santo Domingo River. The Santo Domingo is fed by multiple water sources from various cave systems in the area including the Peña Colorada, Agua Frio Resurgence, HR Resurgence, and the Huautla Resurgence. The Huautla Resurgence was first explored in 1982, followed by expeditions in 1984 and 1995 led by Bill Stone. In 2001, Jason Mallinson and Rick Stanton pushed the cave to a maximum depth of 65m/215 ft and reached a sump pool where a dry cave passage heading off could be seen 10m/30 ft above, but with vertical muddy walls stopping the divers from being able to exit the water. Beyond the Sump, expeditions began exploring the resurgence in 2016 and 2017 where they found an exit from Sump 2 into a dry section, named “Passage of the Cheeky Monkey”, which was thoroughly explored and mapped, with several sumps found along the way. When time ran out for the 2017 expedition, several questions remained unanswered. Primarily, “where the hell does all the water come from?”, as the only source of water seemed to come from a small flowstone restriction affectionately named the “Squirty Hole”. A question that would need to wait five years to be answered.

In late March, 2022, Beyond the Sump set off on another expedition to Santa Ana to find the way on to “Sump 9”. The team consisted of Andreas Klocker (AUT/AUS), Zeb Lilly (USA), Steve Lambert (USA), SJ Alice Bennett (UK/GER), Ben Wright (UK), Rob Thomas (UK) and myself, Jon Kieren (USA), with logistical support happening remotely by Alejandra “Alex” Mendoza (MEX). Bios on the team can be found at: Beyond The Sump-Team. This is a log of our experiences and discoveries.

The team posing during a quick pit stop on the way from Tehuacán to Santa Ana.

28 March, 2022

The entire group met for the first time in Tehuacán. Andreas, Zeb, and Steve had driven down from the US, while SJ and I had driven over from Tulum, and Ben and Rob had flown in from the UK. Everyone’s travel up to this point was relatively uneventful, except for SJ. She had managed to badly sprain her ankle the night before, leaving us questioning how the first couple of weeks of the expedition would pan out for her. Both trucks were packed tight, but room was made for the Brits and SJ’s swollen ankle for the remaining four-hour drive up through the Sierra Madre mountains to Santa Ana. The drive is spectacular, beginning on the north western side of the mountains where it is an arid desert filled with giant cactus and ending at an elevation of about 5200 ft in a lush green mountain forest.

After a quick stop for tacos and to grab a “few” bottles of mezcal, we arrived at our field house after dark. We quickly scrambled to unload the trucks into the concrete box we would call home for the next four weeks. We hastily set up our beds, and a bottle of whisky and mezcal made a few quick passes around the room to con- gratulate our arrival before lights out.

Sunrise view from the field house.

29 March 2022

Church bells rang at 5:30 am which woke both us and the surrounding livestock as the sun began to rise through the canyon below us, a truly remarkable sight that I highly doubted I would ever grow tired of. First order of business was to dig out the coffee pot and tea kettle. Once adequately caffeinated, we started organizing all of the equipment for base camp and diving. We set up a makeshift kitchen with two small camping stoves and a fold-out table. After a batch of scrambled eggs were devoured, everyone started tearing into the dive equipment and getting personal kit and team resources organized. We assembled a boosting station in the field house and set the compressor up outside. Regulators, cylinders, and rebreathers were scattered everywhere, and SJ was busy with camera equipment. Morale was high as everyone made predictions for what the cave was going to do.

Sleeping quarters in the field house.
Andreas organising gear for the first dive day.
Steve packing the truck while brushing his teeth.

Steve, Zeb, and Andreas were supposed to have a meeting with the town council to finalize permission to use the road leading down the canyon and set up operations in the cave. We had no doubts we would gain permission, but it was important to play the local politics and stay friendly with the community. The meeting didn’t happen, but we were assured “mañana” (which often means “later” as opposed to the direct translation of “tomorrow”). Instead of holding the meeting, Steve, Zeb, and Andreas were handed a bottle of moonshine made from sugar cane, called aguardiente. In an effort to be diplomatic, they graciously accepted a drink, and then another. Soon they were hooked into a few hours of hilarity trying to socialize in broken Spanish while the rest of us waited patiently for word on what our plan would be for the next day. We would need to wait until 5:30 am when the church bells rang to assess everyone’s energy levels and see what we thought about the “beg for forgiveness” tactic for finalizing permission before deciding to head down into the canyon or not.

30 March 2022

We decided to go for it and started to set up in the canyon. The 1219 m/4000 ft descent down to the canyon took about an hour by 4×4 truck and was absolutely breathtaking, second only to the hike to the resurgence. The hike was a fairly easy- going 1.2 miles, but took about 40 minutes each way with heavy loads and several river crossings. Luckily, we were able to keep most of the heavy kit in the cave for the majority of the expedition with only CCR bottles, the “cave cascade” (a few lightweight high pressure carbon cylinders we had set up in the cave to refill cylinders), and other little bits and bobs of personal kit needing to be transported in and out each day.

Andreas, Steve, and I did the first dive to reline and survey the first sump and rig the waterfall. Upon surfacing at the waterfall, a wave of “holy shit, this is remote” hit me quite hard, and the smile would not come off my face. While we dove, the rest of the group (minus poor gimpy SJ, who was stuck at the field house knotting line) did two more gear hauls from the truck. Everyone was pretty beat, but nothing a couple Victoria beers and a few liters of gatorade wouldn’t fix.

In the evening, we were able to meet with the local officials for formal permission to use the road and access the cave. We donated some pesos to fund their annual celebration of the anniversary of Emiliano Zapata, which we also had to promise to attend.

Despite Steve’s insistence on K-pop for our daily soundtrack, morale was high.

The 4×4 squeezing out of the narrow driveway on the way to the canyon.
The road down the mountain was often shared with cows and horses. Or broken down cars.
Ben and Jon scrabble over boulders towards the cave.
The second river crossing.

31 March 2022

Day 2 of diving was productive. Zeb, Rob, and Ben were able to set up the gear line for the far side of the waterfall to hang the deep bailouts, run line to 140 feet, and set the deep bailouts. Andreas, Steve, and I did a few gear hauls through the canyon. The next day, Steve and I planned to reline and survey the second sump out another 1200 feet or so at a max depth of about 215 ft. I was excited for the “real” diving to begin.

Rob preparing to go under.

1 April 2022

Instead of the fiery red sunrise through the canyon, we were suddenly in the clouds and surrounded by cold mist, chugging coffee and tea but still struggling to wake up. The group appeared tired from the few days of intense hiking in the canyon, but moods lightened as the coffee hit, and we started to think about today’s dive. After today, we would likely begin pushing the leads left over from 2017 and searching for the way on to Sump 9. I was a bit apprehensive about making it over the waterfall with my Fathom CCR on, and felt a bit jealous of the side mount and chest mount units other team members were using. The waterfall was only about a meter high, but had high flow and razor sharp jagged rocks protecting it. I figured if it was a big hassle, I’d switch out my Flex2 side mount unit for future dives to make getting to sump 2 a bit easier.

On our drive down to the canyon, we were stopped by a group of enthusiastic locals. With big smiles on their faces, they insisted we get out of the truck and follow them up a small trail in the mountainside. As we followed, we could see smoke coming from a pit, and a strong scent of something sweet in the air. The group wanted to show us how they were processing sugar cane to produce piloncillo, an unrefined sugar commonly used in Mexican cooking. We were given a block of the piloncillo, which we later used to make syrup for pancakes and French toast when we started getting tired of scrambled eggs.

Steve and I had a great dive. We crossed the waterfall to sump 2. I made it over with my Fathom on, but it took a bit of effort. I was thinking that switching to the Flex for the next dive would make life easier, especially if we would be hauling more cylinders and scooters over the waterfall. Sump 2 was just a truly stunning, big passage with rolling hills all covered in silt. Our max depth was 56 m/183 ft on this dive, with about an hour of deco to do upstream of the waterfall. We laid another 365 m/1200 ft of line while swimming, setting up the next team to re-line all the way to camp 1 in the Passage of the Cheeky Monkey, and check what was thought to be the most promising lead discovered in 2017, referred to as the “11 meter lead”.

Andreas and Jon during a clean up dive hauling gear back over the waterfall.

2 April 2022

SJ came down into the canyon for the first time today. Her ankle was still in pretty rough shape, but life in the box on the mountainside had become dull. She had been as productive as she could be by knotting line and photographing the town. She also managed to make no less than four new boyfriends, led by a 6-year-old who kept bringing his siblings and friends into the field house and proudly exclaiming “gringa!” while pointing at SJ. He then would lead them around the field house showing off all of the strange equipment we had scattered about.

SJ trying to stay sane while knotting line and being stuck at the field house during the first week.

On our way into the canyon, we were hailed by another group of farmers just a little down the road from the piloncillo farm. As they enthusiastically led us to their farm, we could smell the pungent aroma of fermenting sugarcane before we could see the still. They first showed us how they crushed the sugarcane plants to extract the juice, which we sampled. Rich, sweet, and syrupy, it was hard to get down with the thought of the hard hike through the canyon ahead. Next, they showed us where the fermentation was taking place in large tubs next to the still. We were offered a sample straight from the still, which we had to decline, as there was much work and diving to be done yet. So we promised to stop back at the end of the day to have a drink.

Squeezing sugar cane into juice before the fermenting process.
The team watches with great interest.

The diving for the day proved to be less productive. SJ was able to take some photos of the canyon and divers prepping to enter the cave, but the dive was called early due to a rebreather failure. The line was still extended a few hundred feet, so all was not lost. But the line still did not reach the Passage of the Cheeky Monkey nor had any leads been investigated. Morale was a bit low.

At the end of the day, we stopped back at the aguardiente distillery and were poured a fresh bottle to be passed around. Before taking a drink, Steve asked how much alcohol was in it. The man proudly proclaimed “22 grado,” which Steve interpreted as 22% and took a chug. His eyes went big, he handed it to me, and I took a big swig for myself and quickly realized that “22 grado” does NOT equal 22% as I handed the bottle on to the next person. Realizing we needed to leave ASAP or it would be unlikely any of us could drive the truck home, Rob (who seemed quite pleased with the aguardiente) offered to buy the bottle to take home with us. With the transaction complete, we headed back up the mountain to get to the bottom of this “22 grado” business.

Steve organising his dry suit in front of the cave entrance.
Andreas’ pre-dive excitement.

3 April 2022

Another cold and cloudy day. I was tired, and my back felt broken when heading down the mountain. I needed a day of rest but knew we needed to push on. I switched to the Flex and headed in with Steve on DPVs to line the cave to camp 1 and check the 11 meter lead. I immediately realized I was overweighted with the Flex, steel side mounted bailout cylinders, and extra safeties and deco gas that were to be installed in sump 2.

Crossing the waterfall, I tore the right ankle of my drysuit, which I noticed as soon as I got back in the water on the other side. Knowing I had heated undergarments on and plenty of battery power for the couple hours of deco we might end up with, I decided I would be fine to continue the dive.

With each stage drop, I hoped my stability would improve, but it didn’t. I struggled on, Steve and I making it to the far side of sump 2 to search for the way on to Cheeky Monkey. We made our way up what we believed to be the correct path, doing our deco as we circled up towards an air bell. We did not find the 11 meter lead where we thought it would be, and realized we were in an area known as “Jason’s Eyes,” a dry section first discovered in 2001 by Jason Mallinson which had no way on. Steve asked if I wanted to surface to look around and chat about where to look next, and I reluctantly raised my thumb and pointed back toward the exit. I was super uncomfortable being overweighted as well as needing to dive back to 65 m/215 ft and have an hour or so of deco before the waterfall with a flooded drysuit. Plus, I knew that if we dragged this dive on much longer, I was going to start making mistakes. So we re-descended from our 3 m/10 ft stop and headed back toward Sump 1, when I was abruptly stopped at 9 m/30 ft as I could no longer inflate my wing or drysuit.

Grabbing the cave wall, I realized that the two liter cylinder I had dedicated for wing and suit inflation was dead, clearly a result of struggling with being overweighted and unstable. I got Steve’s attention and communicated the problem, and we started to inventory resources with an LPI connection. We had an O2 bottle, which would not be great for suit inflation considering I was already shivering in the 18º C/65º F water and would desperately need to use my heat during deco. The 50% bottle we were to drop at the deco station heading to camp 1 only had a QC6 connection, which would be no help to me. And that left only my side mounted bailout, which was 15/55 trimix. Certainly not ideal for suit inflation, but better than starting myself on fire. I plugged in and filled my suit with the icy trimix as we started to exit. I had to constantly switch the hose from my suit to wing as we scootered out but managed to make it back to the waterfall with only an hour of deco, which was manageable with my heated vest on full blast.

Jon getting dressed before a not-so-great dive.
Steve getting in the zone.

We were unsuccessful in completing our tasks for the day, and I was in a world of self-pity from my poor decision to change configurations without a shakedown dive. We went back to the field house to conduct some experiments regarding the actual alcohol content of the Aguar. Tomorrow we would rest and re-group. Morale was low.

8 April 2022

The past few days had been challenging. Several attempts at exploration in Sump 2 had proven unsuccessful. We had scoured the deep section, and the fabled 11 meter lead, and others like it, which all pinched off quickly. While there was significant flow coming out of these tight passages, they were simply Swiss cheese that was not passible by humans. Maybe after a few hundred thousand years or so, they would be big enough so we could jam Steve in there to take a look, but for now, we were going to have to focus our search in the Passage of the Cheeky Monkey and the sumps within it to find the way on.

Logistically, this would mean exploring from camp 1 to avoid having to pass a waterfall and do a 65 m/215 ft dive prior to surfacing and hiking gear a couple thousand feet through dry cave to the Sump each day. We would be using the next day as an opportunity to rest and get the first camp team, Rob and Andreas, ready to set off for a couple of days in the Cheeky Monkey.

SJ’s ankle was feeling well enough for her to dive, so we’d done a couple of shakedown dives to test the ankle and get a feel for the cave before starting to shoot the next day.

Steve and Zeb making an aguardiente offering to the cave for good fortune.
Zeb and Steve mixing cave dinner and packing dry tubes for the first camping attempt.

9 April 2022

SJ and I entered the water for a photo dive shortly after Andreas and Rob pushed off for camp 1. About 30 minutes into shooting, we noticed lights and the sound of scooters buzzing toward us. It was Andreas and Rob, obviously having had some sort of problem and aborting early. We decided to exit with them to see if we could assist somehow. Turned out they had a dry tube failure when they made it to the end of Sump 1, drowning most of the camping equipment.

With only 9 days of diving left, and time starting to run out, we couldn’t afford any more mishaps if we were going to figure this cave out. A serious team discussion was had to decide on the schedule for the next few days to prioritize exploration, as well as to ensure that we would have opportunities for documentation. We planned to prep and re-group again the next day, then Steve, Zeb, and I would head into camp 1 for a very long day of poking around in the Cheeky Monkey to determine what the objectives should be for the first camping team.

Steve watching as Andreas and Rob descend on the way to camp 1.
Jon swimming out of the cave though the first arch.
Jon swimming though the double arches in Sump 1.

In the evening, we had a chance to meet up with Bill Stone and his team who were exploring a nearby dry cave. It was pretty surreal to be in Oaxaca with Bill, hearing him tell stories of exploration in the area, as well as to discuss what we had found and what we thought the cave might do. Bill was convinced the Swiss cheese we had found could not be the only water source, as it was rumored that during the rainy season the resurgence produced a geyser several meters tall. We discussed what our plans were moving forward, and Bill seemed to agree that the sumps in the Cheeky Monkey must be hiding something.

10 April 2022

A day of rest and prep for a long day tomorrow. There was a celebration in town for Emiliano Zapata with parades, fireworks, and lots of mescal and aguardiente. It began last night and never really ended. We were supposed to attend the festivities that evening, but hopefully only for a short while as we were planning to leave the field house at daybreak to be in the water early morning.

The music and festivities in town added a joyful feel to the somewhat mixed emotions in the field house. Excitement, stress, and anxiety. Morale was pretty high considering the pressure we were under.

A festive parade walking down the mountain through town.
Tacos were hugely enjoyed by the team.

11 April 2022

A long but successful day. Steve, Zeb, and I pushed off early in the morning and spent the majority of the day in Cheeky Monkey. From the beach where we surfaced, it was about a 30-minute hike through fairly rough terrain, but no serious climbing required. Hauling dive gear did create some challenges, though. We checked Surprise Sump first, which had not been dived before, and it turned out to be the biggest discovery we’d had the whole month. Immediately upon descending, Steve noticed darkness beyond the duck under in front of him. As he shouted for joy through his loop and descended with a line peeling off the reel, hearts started pounding as we realized what might have been right under the team’s noses during the 2017 expedition.

One of the very many o-ring failures during the expedition.

After a hundred feet or so, it surfaced, followed by a short hike and another sump which had an upstream and a downstream, and then another waterfall on the upstream side. Not the borehole we were hoping for, but there was more cave here than we knew about the day before, so that was a huge plus, and it seemed to be heading in the right direction–toward Sump 9. Logistics would definitely get more interesting, but we had a good idea of what resources would be needed for the first camping trip. We exited the water a little after 6 pm with rejuvenated spirits and confidence that we were on the brink of breaking this thing open.

13 April 2022

SJ, Andreas, and I were supposed to do a photo dive today. On our way down the mountain, Zeb’s truck’s suspension started making some terrible noises. When we inspected it, we noticed the leaf spring hanger bracket had torn in half, leaving the leaf spring pressing up into the bed. With no option, we slowly drove the truck back up to the field house to start the process of finding parts and tools. After a quick team meeting, we made new plans based on best and worst case scenarios. Best case would be that the truck was fixed today or early tomorrow morning, and we could get a camping team in to push from Surprise Sump for a few days while SJ and I got as many photos as possible. Worst case, we wouldn’t have time left for camping and would have to do the best we could with a couple of day trips.

A very broken bracket.

SJ and I drove down to Tehuacan to pick up a new bracket while the team tried to get the old one off. At the suspension shop, I was struggling to communicate with the woman at the parts counter. She seemed to know what we needed, I was just trying to verify the part number to be sure we weren’t about to make a 7-hour round trip and return with the wrong part. A kind man waiting in line asked us in decent English what we needed, and I explained. He said, with a sly grin and a wink pointing at the woman behind the counter “she knows”. The woman looked at me and smiled. I shrugged and nodded as she grabbed the bracket and darted off while saying something to our new friend. He told us she took it in back so the shop could press the bushing into the bracket for us. While we waited, we chatted with the man about what we were doing there. He seemed intrigued, was enjoying the stories of our adventure, and I was showing him some photos of caves in Tulum on my phone, when the woman returned with the bracket. As I was paying her, two young men were trying to give SJ a couple sandwiches and pepsis. When she tried to refuse, the woman behind the counter got very excited, gesturing for us to take them. Apparently, when we said we had come 3.5 hours down the mountain to get the part, they were empathetic to our situation. And based on my ragged clothes, matted hair, tired face, and sand-fly covered body (SJ looked great as always), they must have assumed it was quite the journey and refused to let us go away hungry and thirsty.

When we got back to Santa Ana, the team let us know they were unable to pull the old bracket, and that we’d have to take the truck to the nearest town with a mechanic first thing in the morning to try to repair it.

Team discussions in the field house.

14 April 2022

It took until about 2 pm to get the truck fixed, but determined to get some work done, Steve, Zeb, and Andreas decided to push off for camp 1. They were in the water by 6pm, planning to reemerge on the 18th at 4pm.

Zeb stuffing a dry tube with Jon posing questionably in the background.

While driving the truck back up the mountain, I noticed the brakes seemed a bit soft and the steering a bit stiff. However, this was my first time driving Zeb’s truck, and without much other choice, I kept making our way back up to the field house. When we arrived at the house, it was noticed that power steering fluid was leaking below the truck. By then it was after 8 pm, and there really wasn’t much we could do about it at the moment anyway, so we all promptly crashed out so we could get up early and try to sort out the problem in time for SJ and I to finally get in a proper photo dive.

15 April 2022

We topped off the hydraulic fluid but were unable to determine the source of the leak. Ben and I drove the truck around on the more benign roads at the top of the mountain with no noticeable leaks or ill effects on the steering or brakes. So we made the decision to head down the canyon and take some pictures. SJ on the camera, me on lights, and Ben as a model. All went off without a hitch, and the truck made it back up the mountain with still no signs of a leak. I was happy about that, but quite wary. As my dad says, “Problems don’t usually just fix themselves…”

Ben swimming above river pebbles in the cave.
Ben ascending one of the many ups and downs in Sump 1.

16 April 2022

A day for surface photos. SJ had plans to photograph the canyon as well as take some simple shots in the cave entrance. It was a light and easy day that should have wrapped up quite early. However, as we started to pack up and leave the cave for the day, two by two, our entire host family, all 13 of them, started coming around the corner walking toward the cave. It was surreal, we hadn’t seen a single other human in the canyon for weeks, and there out of the blue, was the whole family. Dragging half sleeping children, the happy and excited adults hastily climbed the rocks up to the cave entrance. They were amused to hear that our friends were several kilometers underground and wouldn’t return for a few days yet. After a bit of climbing around, we all started to make our way back down the canyon toward the truck. After the first river crossing, SJ noticed one of the young mothers struggling to carry Liam, the two-year-old. She gave me a nudge, and I turned and offered to carry the little guy. At the next river crossing, we noticed they had a whole camp set up at the edge of the river. As we approached, the young mother offered us a drink, took Liam back from me, and before we knew what was happening, they had reignited the campfire stove and were preparing a late lunch for us. We ate some of the most amazing refried beans on the planet while the kids played in the river until the abuela (grandmother) started packing up a few things. I looked at her and asked “vamos?” (We go?), to which she loudly exclaimed “VAMANOS!” (Let’s go!) With a smile on her face, as everyone scrambled and had camp packed up and were hiking again within moments.

Ben showing the small cavern and explaining that the three missing team members are camping in the cave right now.
Late lunch on the way back at the family’s camp.

After encountering the family, our day suddenly became much longer than we had anticipated. We got home after dark, exhausted from another hot day hiking in the canyon, yet rejuvenated from the experience we had just had. It had been hard to keep morale up with the never ending issues we encountered, as well as less than stellar productivity, but to be able to share a bit of what we were doing there with our caring and supportive host family was truly an experience. They thought what we were doing was truly remarkable, which it really was; it was just hard to remember that when facing failures and adversity. So, a little reminder by way of the smiles on the faces of our new friends gave us quite a boost. We ate dinner quickly and settled in as early as we could. One more shot at cave photos the next day. Before Steve, Zeb and Andreas come out and mess up the vis hauling all of their camping gear out.

Jon swimming into the cave through the first arch.

17 April 2022

SJ and I were able to get in a nice long photo dive. As we were packing up to head out, we saw lights flicker below the surface. Steve, Zeb and Andreas were back a day early, not necessarily a good thing…

Jon’s HUD glowing while swimming through Sump 1.

As they emerged, one by one, there were no high fives or cheers of joy. Just a content look on Zeb’s face as he calmly stated in his mild southern drawl, “she doesn’t go”.

Arriving at camp 1 after 8 pm on the 14th, they had set up camp and prepared for the following day’s explorations. Over the next two days, they scoured the Passage of the Cheeky Monkey and the sumps within.

They dived Surprise Sump, the newly discovered Gold Star Sump, as well as checked the stream way beyond the new waterfall, and searched every corner of the dry cave. The downstream section of Gold Star Sump pinched off into swiss cheese where there was a significant amount of flow. The stream way beyond the waterfall also pinched off into another flowstone restriction, similar to the Squirty Hole. No new sections of dry cave were discovered. Based on observation of the amount and direction of flow exiting downstream Gold Star Sump and the small restrictions in Sump 2, the team estimated it is approximately equal to the flow coming over the waterfall in Sump 1 as well as exiting the resurgence. Concluding that all water sources have been discovered, none of which will allow a human to pass, and no passable dry cave is accessible.

Disappointed, but content that every corner of the Huautla Resurgence had been checked, they decided to close the book on the project and head out a day early.

Visibility got worse with the water levels dropping towards the end of April.

The next few days were dedicated to more photos and cleanup. With 12 safety and deep bailout cylinders remaining in Sump 2, scooters staged at the waterfall, several safeties in Sump 1, six shallow bailout cylinders, rebreathers, and personal gear for seven divers left in the cave entrance, there was a lot of work to do. However, with teamwork, we managed to get everything out of the canyon in just three days. Our backs a bit sore, and our dreams of big going borehole passage beyond Sump 2 unrealized, moods were a mix of relief to be finished and a reluctance to leave, knowing we would likely never have a reason to return to this truly remarkable site.

Completing a project is a bittersweet feeling, of course. While sad there’s no more cave, there’s also a feeling of content completion. We did everything possible to find the way to connect the resurgence to Sump 9 of Sistema Huautla, and we are probably the last team to ever see the inside of the resurgence for the foreseeable future (or ever), which is pretty damn cool. We also had the opportunity to spend time with new friends in a truly remarkable place with extraordinarily gracious hosts. So, in all, I would certainly call this year’s Beyond The Sump expedition a success.

Jon swimming through a tunnel in Sump 1.

Additional Resources:

Wikipedia: Sistema Huautla
Explorers Club:Sistema Huautla, Mexico – the 50-year original exploration and study of the deepest cave in the world
NatGeo:One of the Deepest Caves in the World is Even Bigger Than We Thought

Exploration groups involved with Sistema Huautla:

Beyond The Sump |
Proyecto Espeleológico Sistema Huautla (PESH) 
United States Deep Caving Team

SJ Alice Bennett has been photographically documenting the world around her since she was a kid. After completing a diploma in Graphic & Communication and a B.A. in Visual & Motion Design and moving to Quintana Roo, Mexico in 2017 she’s turned her focus on the underground rivers of the area. Her documentary style of shooting is well known for capturing the emotions of the moment and creating a sense of being there with her. She has a passion for documenting exploration and has worked as a freelance photographer and graphic designer around the globe and just joined the InDepth team. Watch this space.

Jon Kieren is a cave, technical, and CCR instructor/instructor trainer who has dedicated his career over the past 13 years to improving dive training. As an active TDI/IANTD/NSS-CDS and GUE Instructor, and former training director and training advisory panel member for TDI, he has vast experience working with divers and instructors at all levels, but his main professional focus resides in the caves. In his own personal diving, Jon’s true passions are deep extended range cave dives (the more deco the better), as well as working with photographers to bring back images of his favourite places to share with the world. 

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