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by Justin Barbour
Header photo by Justin Barbour
There is always one style of diving that most divers are quick to avoid: Cave Diving. It has developed a reputation as being one of the most dangerous styles of diving in the world, and the divers who do it regularly tend to be categorized as insane. This was definitely my thoughts when I initially signed up for my cave diving class. I was constantly told that cave divers were tempting mother nature to flick them into the afterlife at high speed.
So why sign up for a class that you’re scared of? I was looking for a new challenge. After one of my teammates returned from Mexico from his first cave class it was all he could talk about. I joined him in Florida at the GUE Conference last year and decided to test the waters out in Ginnie Springs at The Ballroom. The moment I passed through the opening and saw the whole room open up I was hooked. The feeling of being able to overcome the fear of the unknown was something I truly never thought I would be able to do and it was incredible. Swimming around the room and looking at the rock work, exploring the cracks and crevasses, experiencing a new kind of darkness, it can easily be seen how addicting this could be. The next day my teammate Fred Espino and I signed up for our Cave 1 class in Mexico.
We trained for months diving as often as we could both during the day and night to simulate the feeling of being in a cave. Running line around rocks, a seemingly endless number of valve drills and s-drills, and fine tuning our positioning kicks to make sure we were ready to hit the ground running when we arrived. After every dive I caught myself thinking “are we really about to fly to Mexico and hop into a cave?” I asked myself that question even right up to the point of throwing my carbon fiber backplate into my pelican case the day before my flight.
Once in Cancun, it’s about an hour-long drive to Zero Gravity (ZG). At times the roads can feel a bit like Mario Kart brought to life, but it only added to the sense of adventure we were embarking on. Once we arrived at Zero Gravity, we were immediately introduced to Christopher Le Maillot and Fred Devos, the two owners of Zero Gravity. Between the two of them they have an uncanny ability to make you feel immediately at home.
There are early mornings at ZG. Before the sun rose on our first day we were up and working on our gear. We had dives planned that day to get acclimated to diving in this new environment and some last-minute rehearsals on skills. We arrived at the Dream Gate cenote and were in awe. We briefed and got our gear together with our guide as fast as possible and climbed down the ladders to get inside of the cave. Once in the water, trying to take in this wild moment in our lives, I realized that any notions of fear that I had were completely gone. It was only the giddy feeling you feel as a kid coming down the stairs on Christmas morning.
As we descended into the cavern, we quickly realized how people can get hurt. Caves are the darkest places on Earth, and yet inspire a sense of wonder. As our can lights cut through the darkness, they begin to reveal the true beauty of the cave. The speleothems, or decorations, are some of the most magnificent parts inside of the caves in Mexico. These stalactites and stalagmites are remnants from when the cave was dry before the last ice age. As we swam through the cave, we realized that we are truly swimming through a frozen moment in time. Looking at the walls you can see the different types of rock layers as they were built up over tens of thousands of years.
The next morning, we got to meet our instructor Laszlo Cseh. We spent most of the first day in the classroom going over theory, the history of cave diving, and the basics for why the rules are set in stone. Laszlo seemed to have an endless supply of examples for these rules in real life scenarios which seemed to be calming rather than alarming to us. That afternoon we drove to our first cenote Xtabay where we got to run through safety drills and such to make sure our fundamentals were down before running our first line into the cave. After a few practice runs in the open water portion it was time to try our first line run into the cave.
The cave initially opened up into a massive room with an enormous triangular rock in the middle of it from the last time the roof collapsed. Once we got to the top of the rock, we were able to tie into the main line and do our initial checks of gas, time, and a quick flow check. Laszlo however had other plans for us. Running up and down the line practicing our kicks to make sure they were perfected for our first official cave dive the following morning. Even that little rush of running the line from open water to the main line was amazing.
The following morning, as with every morning, we were up and downstairs bright and early analyzing our tanks and making sure our gear was good to go so we could get to the cenote first. Upon arrival we quickly set our gear up, listened to the briefing by Laszlo, and walked back into Xtabay for our first official cave dive. Fred ran the line in this time and made quick work up to the main line. From there we were able to proceed into the cave.
One of the first things we realized when in the cave is the vastness of it. Shining our lights ahead we couldn’t see where the end of the beam was, even with crystal clear water. Once we left the entrance, we immediately came to what is known as a Halocline. This is where the saltwater in the bottom of the cave meets with the freshwater creating a false ceiling. As you pass over it, it looks like you’re swimming over a pool inside of the cave. This is something that can play tricks on the mind particularly to a disorientated diver on heading out of the cave.
As we swam through it the fresh and saltwater began to mix clouding the visibility to near zero. Once we staggered on either side of the line however we were able to maintain visual contact with each other, the line, and were able to enjoy the 86ºF/30ºC saltwater that we just dipped into.
The colors in the cave were incredible. The blues and greens were striking as our lights slowly moved about the cave. The rock walls were white in the saltwater, and a tan color in the freshwater.
As we moved room to room, I glanced at my computer and realized we’d been swimming for 30 minutes. While that’s not an unusual time for an open water dive, I rapidly came to the realization of “wait, if something goes wrong, we’re going to have to turn around and swim at least another 30 minutes to get back out.” It was this sobering thought that helped me understand the severity of what we were doing. Nothing a few glances around the cave couldn’t snap me out of the thought and continue on with the dive.
As we continued to swim, we came upon a bed plane section of the cave. This is where the cave narrows, but not too small, vertically and can stretch for hundreds of feet horizontally. As we swam forward, we truly started to feel like cave divers. Alas only a few minutes into the dive we hit our turn pressure and had to exit the cave.
As we surfaced Fred and I immediately popped our regulators out of our mouths and exploded with excitement. It seemed like months of hard work and uncertainty finally paid off in that moment, and it was only day two of the class. Laszlo, in his usual Laszlo calm and collected nature, reigned us in with a subtle, “Meh it was ok, let’s see how you do in the cave.” Little did we know the gauntlet that was ahead of us.
Throughout the class we would arrive first thing in the morning, set up our gear, run through dry drills, gear up, and do three to four dives in a day. Upon finishing those we would drive back to ZG and would be in theory for a few more hours before finally being sprung loose for tacos at Marre Marre across the street. They were very long days to say the least, yet every morning we would wake up before our alarms and couldn’t wait to see what the next set of dives had in store for us.
The next few days were filled with every failure that Laszlo and his trusty bubble gun sidekick could think of. From light failures (primary and both back up lights), to regulator failures, we drilled until it became second nature. On one particular dive we were particularly tested. As we swam through the cave just as we were passing through a thermocline I had a simulated primary light failure. After going through the procedures for stowing, deploying backups, etc. Fred and I turned the dive and started our exit. Suddenly he also experienced a simulated primary light failure and had to go through that process. One thing after another happened honing in our focus to the point where we found ourselves in total darkness. As we stayed in touch-contact we moved along the line as a unit. This shows a level of trust in not only your training, but your teammate as well.
Though as the days went on our confidence began to grow swimming around in the caves. Our awareness began to expand to allow us not only to focus on the team, but also begin to actually see the cave. Looking for the jump lines off the main line, seeing more of the details in the room, genuinely being able to take in the vastness and natural beauty that helped shape these caves over millennia.
On the final day we were tasked with two of the most important skills a new cave diver can learn: lost line drill while blindfolded, and gas share exit while blind. These are skills that hopefully a diver never needs to use, however we are going into a hostile world every time we enter a cave, so it’s important to train for every scenario to be prepared for whatever is thrown our way. In a strange way having the blindfold on elicited a sense of calm like I’d never felt. One hand on the line, the other out in front feeling our way out, with Fred hanging onto my elbow, we moved as a unit through the cave, navigating each station (tie off on a rock) as we moved. It felt like a new puzzle each time we came to a station as we moved our way out.
By the end of the day, Laszlo decided that we’d been through enough and we officially were Cave 1 divers. The feeling was hard to describe for a number of reasons. Chiefly both Fred and I had finally reached the moment we had been training for, studying for, and fearful about. We passed. We were officially apart of that group of divers most people think have a screw loose.
Looking back on what we learned and experienced, it’s clear to see that there are really only a few hard-fast rules to follow, similarly and readily transferable to open water dives, which minimize the risk we take on in the caves. First, plan your dive and dive your plan. This includes careful gas planning, and everyone taking responsibility for their own gear, gas, and navigation. Having a continuous guideline starting in open water, so that even in zero visibility you can always find your way out. Maintain your equipment making sure all regulators, valves, and lights are in prime shape to avoid potential problems in the caves. And lastly, ALWAYS be aware of the mainline. With these in mind one can go around the world swimming through the history books in caves and mines exploring what once was and embracing the beauty of what is.
Diving since 1998 from the Maldives to the Midwest, Justin is a PADI Master Scuba Diver Trainer and GUE Diver who brings a courageous mentality and humorous demeanor to the water. From 2015-2020 he spent countless hours volunteering at the Aquarium of the Pacific applying his expertise to educate children on sustainable ocean interaction.
As a boy he would read constantly about marine biology, wanting to see it for himself he dove right in and has hardly been up for air since. Most intriguing to him is exploring and learning the history of shipwrecks. Justin’s life above sea level includes a career path that has taken him from medical sales to tech startups, every endeavor inspired by the tenacity of being a former collegiate athlete. His goal is to never stop pushing himself, allowing the water to continually reveal character and to share those experiences with others.
Meet The British Underground
It’s cold, dark, you can barely see two meters in front of you, and you’re diving alone. Oh, and there’s a sump up ahead. Welcome to the British Underground! Not exactly a scooter-ride in the warm, clear, stalactite studded caves that lay beneath Riviera Maya. Here British caver and training officer for the Somerset Section of the Cave Diving Group Michael Thomas guides us on a tour of British cave diving and explains why it may not be everyone’s cuppa tea.
by Michael Thomas
Header photo courtesy Michael Thomas. Diver entering Keld Head in the Yorkshire Dales.
Recently someone approached me about British cave diving wondering what in particular makes it so very different from Mexican cave diving, for example, and why it’s so appealing to a select few. In the U.K. we have two types of underground diving. The first is the significant number of flooded mines that have given rise to some world-class mine diving that’s becoming very popular with technical divers from around the world. The second type of underground diving is traditional British cave diving, which, due to the nature of U.K. caves, involves both dry caving and cave diving. The aim is to explore the caves underwater or in the dry underground following it as far as possible. We are now finding that technically trained mine and cave divers are starting to learn the art of dry cave exploration in order to further their knowledge and adventure, some even gaining enough experience to join the Cave Diving Group in the U.K.
Firstly, a little about myself if I may be so bold. My diving career is now in its thirty-third consecutive year, from starting out as a trainee open water diver with BSAC to trainee cave diver within the CDG to becoming the Training Officer of the British Cave Diving Group Somerset Section in the U.K. Since 1996 I’ve had links to TDI and currently hold Full Cave Instructor, Sidemount and Tech Instructor status with TDI, active mod 3 CCR cave diver, and on the British Cave Rescue call out list as a diver.
My diving life crosses all paths of British and worldwide diving, from open water to cave and tech. I’m actively involved with technical diving conferences and a fellow of the Royal Geographic Society of the U.K. My father was a cave explorer before me, and my son has also taken the same path. You could say, caves and diving are our lives.
See The CDG
To understand British cave diving we first need to understand the CDG. The Cave Diving Group is the representative body for cave divers in Great Britain and Northern Ireland and is a constituent body of the British Caving Association (BCA). Its function is to educate and support cavers for recreational and exploratory operations in British sumps. The CDG also helps control access to numerous cave sites, including Wookey Hole and Gough’s Cave in Somerset, and Keld Head And Hurtle Pot in Yorkshire, in conjunction with the BCA. The group was formed in 1946 by the late Graham Balcombe, and its continuous existence to the present day makes it the oldest amateur technical and cave diving organization in the world. Graham Balcombe arguably invented cave diving in the U.K. with his audacious dives in Swildon’s Hole cave and Wookey Hole cave in 1935.
Now the huge difference between the Cave Diving Group and other cave diving training agencies is you can’t just sign up and pay to do a training course. From the very start in 1946, the prerequisite for joining the CDG was always and is a knowledge and experience base of dry caving skills, though in modern years we also require an open water certification. Once you have made yourself known to one of the four sections that make up the CDG—Somerset, Welsh, Northern, and Derbyshire—and proven you have dry caving skills and can get along with your new-found friends, you are voted in, hopefully to whichever section you approached.
As a trainee member of the cave diving group, the training is apprenticeship based and generally takes between 12-18 months. At the end of that, a written exam and an underwater test is completed, and as long as your section is in agreement, the qualified diver status is awarded. It’s a slow process but ensures adequate experience is gained in a variety of different sites and conditions, producing a cave diver that is capable of exploration cave diving, rescue work, and continued training of new members.
The Solo Mentality
Probably the one difference with most U.K. cave diving, that is a world away from agency standards, is the CDG approach to team diving. In all but a few sites in the U.K., the CDG considers solo diving the safest way to approach the dive. While divers might enter the cave together as a team, and dry cave their way to the dive base (dive site within the cave), once they are in the water they typically dive solo. This is because a diver is usually unable to help another diver in the water. Then they meet up on the other side if more dry caving is to be done.
CDG trainee divers are taught from the beginning to be solo divers or work within a team as solo divers, something we call “team solo.” Most dive sites in natural caves in the U.K. are unsuitable for team diving. The few sites that are suitable for a team to operate together, such as Wookey Hole in Somerset, Hurtle Pot in the Yorkshire Dales, and Porth Yr Ogof in South Wales, should really be a team of only two divers. Passage size and visibility generally means divers can’t see the third team member if at the back or front of the team. The mine diving sites are much more suited to team diving with larger passages and clearer water. The links below offer more information on mine diving in the U.K. [Ed.note: Global Underwater Explorers does not sanction solo diving.]
The article, “Solo Cave Diving,” on the CDG website explains why it recommends solo cave diving as the safer alternative for U.K. sump conditions. It lists some of the advantages of solo cave diving as follows:
- There’s no one to get physically jammed in the passage behind you (thereby blocking your exit).
- There’s no one behind you who may get tangled in the line and have to cut it—leaving you with no guide home.
- There’s no one to accidentally disturb your ‘out tags’ at line junctions (e.g. in one cave there are 10 branch lines off the main line in the first 500 m/1640 ft of passage).
- There’s no one to cause silt problems (but yourself).
- There’s no chance of being called upon to share air—in small passages.
- There’s nothing to get confused about—communication in sumps varies from difficult to impossible.
- There’s no one to provide you with a false sense of security.
- There’s no one to worry about but yourself, so you can concentrate on your own safety.
Due to the generally small passage size of British caves and the sometimes energetic nature of transporting equipment to a cave dive base (station), sidemount diving is the normal equipment configuration. Sidemount started in the U.K. in the 1960s with a need for streamlined and lightweight diving equipment. U.K. cave divers today will have a choice of sidemount harness for the project they are involved with. In a short, shallow, or constricted dive, the diver will use a wetsuit and a lightweight, webbing-only harness with no buoyancy, as it’s not needed if your chest is on the floor and your back on the ceiling.
In slightly larger cave passages, the modern British cave diver will use one of the now-common sidemount harnesses that are available. Many British caves require vertical cave techniques to reach the water, so the divers have modified the sidemount harness to be able to descend into the dry cave, do the dive, and then climb out. It’s very rare to find a British cave diver with an unmodified sidemount harness. For exposure suits, many short dives and some longer dives, if significant dry caving is expected before or after, the dive will be done in a wetsuit even though water temperature is on average between 7-10 degrees C/45-50 degrees F. This is for practical reasons, as it’s very difficult and potentially dangerous caving in a drysuit, so better to be slightly chilly during the dive and caving safely.
For larger sites and when the diver is expected to be underwater most of the time, a drysuit is sometimes carried to the dive base and put on underground, to be utilized for the dive. As most divers are solo diving, having two short standard-length hoses on their regulators is normal, although for team diving or cave rescue, a standard long hose is used on the right.
British cave divers always use helmets, as they provide protection from the environment in the dry caves as well as underwater, and are a great place to carry lights. Hand-held primary lights are used in larger, clearer passages with the helmet lights in reserve. For dive lines, we use 4 mm thick lines as permanent dive lines and we have fixed junctions in all caves— no jumps or gaps. Standard line arrows and cookies will not fit on a U.K. line. Pegs are used, or permanent markers on junctions to show the way home. It’s very unlikely you will see another dive team in the cave on the day you are visiting, and following a thicker line in sometimes low visibility and cold water is much safer and more comforting than trying to follow a technical diving line.
Exploring U.K. caves
The raison d’etre for the Cave Diving Groups formation was and still is the exploration of caves, including the surveying and reporting of that exploration and the training of new divers. The CDG publishes a journal four times a year with exploration reports and many books on the subject of U.K. caves and techniques. If it’s not surveyed and reported, it’s not explored. Now, it would be extremely tedious to the reader if I listed all exploration in underwater caves in the U.K.—we have thousands of reports—so I’ll mention a few of the classics to set the scene, and remember all exploration can be researched in the CDG journals.
If visiting, most U.K. cave divers are happy to show you around or even get you involved in projects, although they will be of a very different style of exploration than found in Bahamas or Mexico, for instance, where swimming into hundreds of metres of new cave is possible. Big breakthroughs in the U.K. are rare, and if a diver explores 10 m/33 ft of new cave with ongoing passage seen, they will be happy.
Exploration in the home of British cave diving started in 1935 and carries on to this day. Slow and determined work by some of the great names in cave diving, including Balcombe, Martyn Farr, Rob Parker, Rick Stanton, and John Volanthen have seen this multi sump cave reach 90 m/294 ft depth beyond chamber 25 in extremely committing passages. Smaller side passages throughout the cave are still being explored.
The Llangattock Cave Systems, South Wales
Under Llangattock mountain lies many kilometers of caving—two caves, Ogof Daren Cilau at 27 km long and next door Ogof Agen Allwedd at 32.5 km, provide access to many cave diving sites that have provided incredible exploration over the years and will hopefully provide more in the years to come. One of the longest dives in the system is the Pwll y Cwm resurgence at 630 m/2066 ft long, surfacing in the downstream end of Daren Cilau.
Kingsdale Master Cave and Keld Head, Yorkshire Dales
One of the true classics of world class cave diving is the Kingsdale to Keld Head system. Graham Balcombe, of Wookey Hole fame, conducted dives in 1945 in Keld Head, and in 1978, Geoff Yeadon and Oliver Statham broke the world record with an 1829 m/6000 ft dive between Kingsdale Master Cave and Keld Head, connecting the two caves. In 1991, the underwater system was further extended, linking it into King Pot cave access to the valley floor, a traverse of 3 km in British conditions. Today, divers continue to explore and extend this system.
This dive site requires a reasonable amount of dry caving effort to reach the dive base. The dive itself is multi-profile with a descent to 36 m/118 ft then up to 2.5 m/8 ft via a constricted rift, then finally down to 71 m/232 ft at the end. In the 1980s John Cordingley and Russel Carter worked the site and finally, 71 m/233 ft was reached by Martin Groves in 2002. The way on was lost in boulders and boiling sand with the water surging upwards. This was confirmed by John Volanthen in 2006. A change in geology and future technologies await.
In the years leading up to the 1980s, open water divers reported cave entrances in the sea on the Doolin coast. These completely submerged caves are extremely weather dependent due to taking the full force of the Atlantic Ocean. But after experience gained in the Bahamas’ Blue Holes, British divers tried their luck exploring what became known as Green Holes. Several sites including Reef Caves, Hell Complex, Urchin Cave, and the longest Mermaid’s Hole have had successive and continued exploration. 1025 m/3350 ft penetration being reached in Mermaid’s Hole by Artur Kozlowski. Exploration continues when the weather allows.
A true classic sump diver’s cave with long sections of active wet streamway takes the visitor down to a series of eight short sumps that require diving and more caving to reach the terminal sump and end of the cave at Swildon’s 12. Wetsuits and lightweight sidemount harness and small cylinders needed. A grand day out.
One of the finest and reasonably easy physical-access cave dives in the U.K. The dive starts from a small pool after a short climb down between boulders. A shallow and comfortable passage winds its way up the valley passing Rawlbolt Airbell 150 m/492 ft from base and Four Ways airbell around 200 m/656 ft from base. At 250 m/820 ft from base, a cobble squeeze can be passed to the surface in the dry upper cave. The flow in this cave can be very high and the passage size varies from 1 m wide to 3 m wide, making progress upstream interesting and downstream on the return exciting.
Probably the most dived cave in the U.K. due to its easy access and the possibility of longer dives upstream in a large passage towards Jingle Pot Cave and an area called The Deep reaching 35 m/114 ft depth in a low complicated passage towards the end around 460 m/1508 ft from base. Downstream a 400 m/1312 ft long traverse can be made to surface in Midge Hole cave reaching 20 m/65 ft depth on the way. This cave floods dramatically in bad weather, and constant line repairs need to be made by local CDG divers.
Peak Cavern is an extensive dry cave with several significant cave diving sites located within the system. The resurgence is a classic training dive in a lovely bedding plane style passage reaching the surface in the main cave. Ink sump within the cave, nearly 200 m/653 ft long, leads to Doom’s Retreat, an area worked by Jim Lister and the most extensive digging project to find a new cave beyond a sump in the U.K. Far Sump at 385 m/1263 ft long leads to an extensive dry section of cave with some extremely technical caving that can now get you to surface on the hills above.
Not many easy surface access cave diving sites that go deep are to be found in the British Isles, but this one in Ireland is one. A resurgence site that reaches 103 m/336 ft but in dark, unfriendly waters. Original exploration by Martyn Farr in 1978 and taken to 103 m by Artur Kozlowski.
In summary, British cave diving is historically one of the oldest branches of the sport of cave diving. The Cave Diving Group’s knowledge and standards and procedures evolved over the years to the safest method to explore or dive in U.K. style caves. It is not diving in Wakulla Springs and does not pretend to be, although several CDG members got involved in the early Wakulla expeditions. It is at times cold, wet, and unpleasant, but also can be extremely rewarding, with new caves found or just a superb dive in excellent conditions. U.K. style conditions can be found all over the world—think of the Thailand Rescue in 2018—and it’s in these conditions that the CDG system is at its best. If you’re wanting more information on the CDG or sump diving and vertical access sump diving, please give us a shout. Just remember—a pint of English beer is supposed to be warm. Stay safe and dive well.
Website: The British Cave Diving Group
From GUE’s membership magazine QUEST: “British Cave Diving: Wookey Hole and The Cave Diving Group” by Duncan Price
Books about British cave diving:
A Glimmering in Darkness by Graham Balcombe
The Darkness Beckons by Martyn Farr
Historical British cave diving films:
Trailer for documentary film ‘Wookey’ by Gavin Newman
The Underground Eiger (1980s)
Articles by Michael Thomas:
Michael Thomas’s diving career is now in its 33rd consecutive year, from starting out as an open water diver then a trainee cave diver to becoming the Training Officer of the British Cave Diving Group Somerset Section. He is also a Full Cave Instructor, Sidemount and Tech Instructor with TDI, active mod 3 CCR cave diver, and on the British cave rescue call out list as a diver.
Thomas is heavily involved in U.K. diving projects and training, plus overseas diving and caving. Diving is life or is life diving?
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