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Open Circuit Technical Diving Is Not Dead



by Richard Taylor. Images courtesy of Rob Wilson unless noted.

Hindsight can be sobering. Eight years ago, I argued open circuit (OC) technical training was becoming obsolete because of the push toward closed circuit rebreathers. Turns out, I was a bit aspirational, and wrong. We’re still not there—not even close. And maybe we will never be. 

A version of the piece, “Is There Still A Case for Open Circuit in Tech,” was first published in X-Ray Mag #70 in 2015, back when the question—Is Open Circuit Technical Diving Dead?— was about whether the push toward rebreathers would mean the end of OC training. Now, with rebreathers (CCRs) seemingly even more ubiquitous in technical diving, the question about whether there’s a place for open circuit at all is even more pertinent. 

Ask a CCR diver (a passionate bunch, to say the least) and they’ll likely dismiss the need for open circuit technical training. Many divers are swayed by the potential deep dive cost benefits, often brought on from CCR divers highlighting gas costs, longer bottom times and shorter deco. But most CCRs are not yet at the stage of CCR redundancy, and OC skills remain the primary backup for these divers. 

Some experienced CCR divers are arguing against the need for such training, even though they have likely had extensive OC training themselves, on which they will be able to lean if their rebreather fails and they have to bail out. Simply put, these experienced divers are asking new divers to take a risk they don’t have to take themselves.

As such, open circuit still has an important place in technical diving. Not only is OC technical diving alive and thriving in some areas, but we need to consider that OC technical training should be mandatory for all technical divers, even those diving on CCR. 

Where are We Heading?

Eight years ago, I wrote the following in a previous version of this article (edited for clarity):

“Excluding global disaster, you have to say that the CCRs are here to stay, and will only become more entrenched. More CCR manufacturers will enter the market with a resultant drop in prices as competition increases. The move to “Recreational” CCRs will increase as both established and new CCR manufacturers see this as a profitable share of the market, resulting in more retailers investing in this area to increase their own sales. 

As the recreational CCR market builds and unit price drops more divers will move along the CCR pathway. Divers will be drawn to CCR Training sooner and CCR Programs will become less reliant on any OC prerequisite. 

Of course, the rate at which this will occur will depend upon many forces, some internal in diving, some external. However, one thing is certain, CCRs are probably not going to go away.”

In eight years, not much has changed—except that the CCR lobby has grown even louder. As we continue to see a greater focus from the industry on CCR, we are seeing a need for easier unit crossovers, and potentially even a need for basic unit standardisation. But, along with this, we are also seeing a decline in OC skills for CCR divers. 

CCR hype has reached a crescendo. New CCR models are being introduced regularly (25+ mainstream agency recognised units at last count) with multiple tech units, “Type R” (recreational) and semi-closed and closed circuit variants for specific needs. We now have a European Rebreather Standard (EN14143) and RESA, the Rebreather Equipment & Safety Association.

Alongside this, the training agencies have pursued CCR divers with their usual commercial vigour, and there is a well-worn pathway allowing divers to develop along the technical side on CCR, often with little, if any, requirement for OC tech qualifications. Today’s aspiring technical diver Can be CCR trained with nothing more than four open circuit dives as an open water scuba diver.

CCR Training Alone Is Not Sufficient

In looking at current programs, CCR training courses need to include a stronger focus on core OC options such as OC gas consumption rates and dive planning. OC technical skills should be regarded as a mainstay of CCR diving as pretty much every CCR course still teaches bailout to open circuit. 

Many CCR divers, sadly, often portray OC tech diving as obsolete, like needing to learn how to drive a manual stick shift when you get your driver’s license. In other words, just learn in an automatic. They say that if you dive CCR, you learn how to plan an OC bailout, and that it makes more economic sense to just go CCR from the beginning. 

Lauren Fanning in Upstream Emerald Sink holding a line arrow from former WKPP director George Irvine. Photo by Kirill Egorov.
Lauren Fanning in Upstream Emerald Sink holding a line arrow from former WKPP director George Irvine. Photo by Kirill Egorov.

But keep in mind, virtually all of the divers making that argument still have OC training to fall back on in an emergency but it remains to be seen how the lack of that training will affect up-and-coming CCR divers. After all, how many CCR divers actually have a bailout CCR? 

OC Tech Training Remains Relevant

If we look at most current CCR training courses, there appears to be a need to include a stronger focus on core OC options such as OC gas consumption rates and dive planning. OC technical skills should be regarded as a mainstay of CCR diving as pretty much every CCR course still teaches bailout to open circuit.

Let’s not forget the size of the OC and OC technical market. Significant, upfront investment, access to training, rebreather support and services are critical to becoming a successful CCR diver. I don’t know if anyone has done a study on the untapped or latent technical diving market size, but I can use SDI/TDI President of International Training Brian Carney’s 2016 DEMA presentation on “How Big is the Technical Diving Market?” His data indicated that the ratio of OC tech vs. CCR tech was roughly 6:1. There are six OC tech divers to every CCR diver!

We must also recognize the inherent privilege embedded in the question about whether OC tech diving is dead. Diving isn’t a cheap sport by any means, but most divers don’t have the luxury of being able to buy a rebreather and support its ongoing costs and maintenance. CCRs might over time lessen the costs of tech diving, but not before a diver forks over what amounts to a year of college tuition for the unit and training. So maybe the CCR divers who are calling for the end of OC tech need to consider their own CCR privilege.

In time, CCRs may well dominate resorts, boats, and diving operations around the world, and there may emerge another bailout option for CCR divers i.e., rebreather bailout. 

But until that time comes, OC will be the “go to” option, and if we allow our CCR divers to progress through tech without sufficient OC skills, we are not only doing them an injustice but ourselves. There are currently about 20 CCR Fatalities each year (pre COVID). It is when things go wrong that we often say to ourselves, “If only I’d done or said that.”

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We began the discussion on OC vs CCR here (June):

Will Open Circuit Tech Diving Go the Way of the Dinosaurs? By Neal Pollock

GUE and the Future of Open Circuit Tech Diving By Ashley Stewart

Is deep, open circuit tech diving destined to share the fate of the spinosaurus? Complete our short survey: OC v CCR to find out.

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X-Ray Mag: Is There Still A Case for Open Circuit in Tech by Richard Taylor (2015)

DIVER mag: Rise of the Recreational Rebreather by Michael Menduno (2014)

TDI Blog: How Big is the Technical Diving Market? by Brian Carney

Technical Diving Instructor Trainer, Co-founder of TDI & SDI in Australia & NZ, and OZTeK Founder Richard Taylor may not be a diving dinosaur, but he has been around long enough to remember some of them!

Richard has over 30 years’ experience in technical diving (25 as an IT) including some of the first trimix dives in Australia in 1994 (before certifications were available). He was Regional Director for TDI/SDI Australia/NZ for over 15 years and founded or was part of many early technical diving projects in the region. He also founded & ran the acclaimed OZTeK Conferences from 1999 to 2007. 

Richard has taught hundreds of technical divers and Instructors around the world and continues to teach today for SDI/TDI/FRTI and is one of the few Instructor Trainer Evaluators.

He is not afraid of voicing a strong view on subjects and, as a past rebreather diver & instructor, is a passionate advocate for training and maintaining open circuit technical diving skills. His strong belief is that as we gain more experience we gain a responsibility to pass our knowledge and skills on to others so that those who come after us can go further than we have, and come back and tell us their story!

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The Aftermath Of Love: Don Shirley and Dave Shaw

Our young Italian poet-explorer Andrea Murdoch Alpini makes a pilgrimage to visit cave explorer Don Shirley at the legendary Bushmansgat cave in South Africa. In addition to guiding the author through the cave, Shirley and Alpini dive into history and the memories of the tragic loss in 2005 of Shirley’s dive buddy David Shaw, who died while trying to recover the body of a lost diver at 270 m/882 ft. The story features Alpini’s short documentary, “Komati Springs: The Aftermath of Love.”




Text by Andrea Murdock Alpini

Inside the Black Box of Boesmansgat’s dive archive (Dave Shaw memorabilia)

🎶 Pre-dive clicklist: Where is My Mind by Pixies🎶

South Africa, Komati Springs.

On October 28, 2004, two cave divers and long-time friends, Don Shirley and David Shaw, planned a dive at Boesmansgat (also known in English as “Bushman’s Hole”) a deep, submerged freshwater cave (or sinkhole) in the Northern Cape province of South Africa. Dave dove to 280 meters, touched the bottom and started exploring. At that time, Shaw had recently broken four records at one time: depth on a rebreather, depth in a cave on a rebreather, depth at altitude on a rebreather, and depth running a line. While on the dive at Boesmansgat, he found a body that had been there for nearly ten years, 20-year-old diver Deon Dreyer. 

After obtaining permission to retrieve the body from Dreyer’s parents, the two friends returned three months later. They enrolled eight support rebreather divers (all of whom were close to Don) and Gordon Hiles, a cameraman from Cape Town, who filmed the entire process—from the preparation on the surface to the operation at the bottom of the cave. The surface marshal was Verna van Schaik, who held the women’s world record for depth at the time. Little did they know that Dave would not come back from his 333rd dive, one that he himself recorded with an underwater camera. 

Researchers have determined that while attempting the retrieval, Dave ran into physical difficulties with the lines from the body bag and the wires from the light head. The physical effort of trying to free himself led to his death for what is believed to be respiratory insufficiency (see video below). Don Shirley nearly died as well, and apparently was left with permanent damage that has impaired his balance. 

Nearly 20 years later, our own Andrea Murdock Alpini visits Don and has this to say: 

Dave and Don before a dive.

February 2023—I arrive at the mine owned by cave expert and pioneer of deep diving, Don Shirley. The place is fantastic—the wild nature, the warm water, and the dives are amazing. Every day I spend at least 230 minutes underwater, filming the mines and what is left of man’s influence in this beautiful and God-forgotten corner of Africa. Every day I have time to talk, plan dives, and prepare the blends together with Don Shirley. 

The following is a part of the story that links Don Shirley to South Africa. Stories and places intertwine between Komati Springs, Boesmansgat (or “Bushman’s Hole”) and then the fatal dive with his friend Dave Shaw. 

Monkeys arrive on time every 12 hours. They showed up last night at about 5:00. They came down from the trees in large groups. They start playing, throwing themselves from one branch to another, chasing each other. Mothers hug their little ones. Some of them play with oxygen cylinders, the smaller ones instead with methane gas tanks, the ones we use for cooking. We are surrounded by gas blenders of all kinds. 

A herdsman’s hat rests on the workbench. Two hands with delicate, thin skin take adapters, cylinders, and whips.They open and close taps. Notebooks report all the consumption for each charge, strictly written in liters with the utmost precision. Impressions: An Amaranth t-shirt, an unmistakable logo, that of the IANTD. A pair of jeans and then some boots. He has a slight physique, he is lean and athletic with a beard that is white now, and a few days’ old. 

While he works carefully, I do not disturb him, for I know well that when mixing, one is not to be interrupted, at least this is so for anyone who loves precision. Then, when he’s done, we have time to talk a little bit together.

Don Shirley with the author planning a dive at Komati Springs

We sit at his desk and then go to the board to plan the dive in the mine.

Don shows me the map of the first level. He explains some important facts to me, then his hands pull out a second sheet with the plan redesigned from memory of the second level at 24 m/70 ft deep. “This is the guitar level,” he says. 

At first I don’t understand. He chuckles. I look at the shape he drew and, yes, that floor plan is a cross between a Fender Stratocaster and a Picasso guitar. Anyway, it’s a guitar, no doubt.

We begin planning the dive together. It’s exciting to hear him talk; he speaks in a soft, elegant tone, and it moves me. I look at his index finger moving. I listen to his words, but I also look at his eyes. 

He gives me some advice but also tells me, “This mine is more similar to a cave. I have left it as it is. I want people to explore it and not follow any lines.”

Freedom of thought, plurality of choices. Acceptance of risk, inclusion of the other in what belongs to you. It’s clear that Don’s vision of diving is uncommon. Freedom is beautiful, but it is the most dangerous thing there is, if mishandled. 

An old map of Komati’s mine site

The next day, we have an appointment at 7 o’clock at the lake. Before diving this morning, we saw where the “Tunnel of Love” originates on the surface, a curious gallery which I came across underwater. There are two parts of the mine that survived the destruction of the mining facility after its closure. One of these is the tunnel where we are going, the other part is perched in the middle of the mountain.

Don explains that the tunnel is now frequented by the wild animals who go to drink there, so we follow their trail. The water has flooded everything up to just a few meters below the surface of the bush. Don cuts the underbrush that makes the path difficult. He wears his faithful herdsman’s hat and never takes it off. The ground begins to tilt slightly, a good sign that we are about to arrive. A series of stones suggest that here the path has been paved. “It was covered in wood,” Don explains.

The path that started from the building where the miners lived is now demolished. Following it, we arrive at what was called “The Tunnel of Love.”

The tunnel that was the mine’s main entry point. Narrow and difficult, the tunnel led to level one—now underwater at a depth of 18 m/60 ft.

We turn on the headlamps and enter. A small colony of bats flaps its wings upon our arrival. The water touches our boots. Some roots filter from the rock and stretch to the resurgence. The scenery is evocative.

The author and Marco Setti in the end of their explorations at Komati Springs

Don kneels, peering at the water, and something. He looks at the water and something changes within him. Something has changed in our shared dialogue.

It’s as if Don takes on another language as he speaks. He always looks straight ahead. His vocabulary changes, and with it his tone of voice. We talk about politics, economics, the future of Komati Springs, the origin of the name of the place, the history of the mine, but we never mention two topics: diving and Dave Shaw.

Don’s a real caveman. I know that those who love caves are not ordinary people. We who do are a little bit mad to do what we do and love, but he’s different. He is comfortable here; he has found his dimension.

I remember asking him a question when we were inside the Tunnel of Love, breaking one of the long silences: “What thoughts are going through your mind?” He seemed to have reached a meditative state, a kind of catharsis. He replied, “I am just relaxing. This is a peaceful place. “

Around nine o’clock, we travel again to the lake, leaving the dry caves behind. 

Exploring a tunnel in the flooded mine.

The first dive lasted 135 minutes, the second 95 minutes. Once the equipment is set up, I return to the cottage to dry everything and recharge the cylinders.

Don’s hands this time are again without gloves. Before we start mixing, we walk into his office.The walls are lined with articles he has published over the years. 

He shows me the medals for valor he got when he was on duty in the British Army. When we return to a small corridor that acts as a barrier, my eyes fall on two photographs. “Is that Dave?” I ask. “That’s him. We were here in Komati,” Don tells me. “You see? This is his hat,” and he points to what is on his head.

The pond above the mine and wild nature who surrounds Komati. A real wild South Africa scenario.

The Consequences of Love

These are the consequences of love, I think. A friendship that transcends time, life, but also death.

It’s time to prepare the blends for tomorrow. As the oxygen pumps out, Don asks me, “Have you ever seen our Boesmasgat’s diving slates?” Obviously, I had never seen the decompression tables of that famous and tragic dive to 280 m/920 ft depth at 1,600 meters (nearly 5,000 feet) altitude.

“Hang on a sec.” Don picks up a small black box with a yellow label and brings it to me. He opens it. “These are the original dive charts. These are mine; these are Dave’s.” The box also contains the famous blackboard with the inscription, (“DAVE NOT COMING BACK”) from the documentary, as well as a pair of underwater gloves used in that dive, and then the heirloom of his CCR computer that broke due to excessive hydrostatic pressure.

He exits the room. He leaves me with those emotionally charged objects in my hands. I can’t see them any differently. They obviously have historical value; but, for me, the human sense prevails. I look at the decompression tables, touch the gloves, and think about the hands that wore them, that read the various whiteboards, and I imagine the scenes of that time.

Early days of explorations at Komati Springs, Don Shirley with Dave Shown and their team 
Don Shirley wearing Dave’s old hat while scouting out the Tunnel of Love

I place everything back in the box. I hand it to Don as I would hand him a precious urn. In part, it is one. I find it hard to express myself in that moment. He understands why.

At this point I ask him, “What was the true meaning of that extreme dive that Dave wanted to do? Why did he do it?”

“He just wanted to explore the bottom of that cave,” Don said. “Wherever Dave went, he wanted to get to the bottom. That’s how we’ve always done it together. So that’s what we did here at the mine.” 

Don then tells me a series of details and information about that place, about the geological stratification of the cave; he talks a little about the owner of the land where the famous sinkhole is located, and finally he talks about many other aspects of their failed dive. I promised to keep it to myself, and I will do so, forever.

Such is a connection that endures over time.


Wikipedia: Dave Shaw

YouTube: Diver Records Doom | Last Moments-Dave Shaw

Wikipedia: Dave Not Coming Back (2020) A critically acclaimed film that centers on diver Dave Shaw’s death while attempting to recover the body of Deon Dreyer from the submerged Boesmansgat cave in 2005.

Shock Ya: Don Shirley Fondly Remembers Scuba Diving with David Shaw in Dave Not Coming Back Exclusive Clip

Outside: Raising the Dead (2005) by Tim Zimmerman

Other stories by the prolific Andrea Alpini Murdock:

InDEPTH: Finessing the Grande Dame of the Abyss

InDEPTH: Hal Watts: Plan Your Dive

InDEPTH: I See A Darkness: A Descent Into Germany’s Felicitas MineInDEPTH: Stefano Carletti: The Man Who Immortalized The Wreck of the Andrea Doria

Andrea Murdock Alpini is a TDI and PSAI technical trimix and advanced wreck-overhead instructor based in Italy. He is fascinated by deep wrecks, historical research, decompression studies, caves, filming, and writing. He holds a Master’s degree in Architecture and an MBA in Economics for The Arts. Andrea is also the founder of PHY Diving Equipment. His life revolves around teaching open circuit scuba diving, conducting expeditions, developing gear, and writing essays about his philosophy of wreck and cave diving. He published his first book, Deep Blue: storie di relitti e luoghi insoliti (2018) and IMMERSIONI SELVAGGE, published in the Fall of 2022.

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