Text: René Lipmann 

Anton van Rosmalen likes to explore caves and tunnel systems where no human has ever been. He uses scooters to go further and deeper than an average cave diver will ever attempt. On Duikvaker he provides the presentation 'Cave Diving: Lessons Learned.'

How, when and why did you start cave diving? 

I started diving in the late 80s. I quickly got tired of it. I started to get tired of putting on a frozen wetsuit naked on a snowy dike in Zeeland. Around 2003 I wanted to start diving again because of a holiday to Costa Rica with friends. At Ben Stiefelhagen's diving school I discovered wreck diving at sea. However, I soon had my doubts about the equipment I was using. I soon realized that my equipment, more like a 'Christmas tree', was not suitable for narrow passages. Furthermore, I also had my doubts about some of the procedures that were used and taught. In search of answers I ended up in the GUE/DIR scene where I came into contact with cave divers. I followed my GUE Cave1 in 2006 and from that moment on I disappeared underground more and more often.

Were you bored of wrecks? How come you feel truly at home underground?

I still love wreck diving, mainly because of the history. They are real time capsules. I just suffer terribly from seasickness! So I have little interest in shipwrecks as long as they haven't sunk and are still lying around on the waves with me on board. Also, many wreck dives are cancelled due to bad weather. Fast charters have become so expensive due to the high price of diesel that it is also possible, in terms of cost, to drive to France and go into caves there.

My first cave dive was in Source de Landenouse (Lot, France) during my Cave1. I was allowed to go first and was immediately sold. During that first dive we did not go further than 50 meters into the cave because I really wanted to look at every stone extensively. Caves felt like coming home, I was immediately sold, no idea why. The feeling of being able to float around in a tunnel filled with Spa was just so magical. 

You are one of the most active and experienced cave divers in the Netherlands. 

Where do you mainly practice cave diving? 

Most of my cave diving is in the Lot, the province in the South of France next to the Dordogne. The caves are reasonably accessible and very beautiful. However, there are also great caves in the Doubs, Ardèche and around Marseille. In addition, you can do wonderful cave diving in Croatia, Italy, Spain, Switzerland, Mexico and Florida. The Ardennes also have particularly beautiful mines and somewhat adventurous caves to dive in. Another special place is the Hérault in the South of France, where we have been active with a small team for many years in a row exploring and mapping Évent de Coudoulière. 

What is special about this cave? How do you get permission to dive there? 

Coudoulière is the drinking water system for the village of Pégairolles-de-Buèges. So in principle you are not allowed to dive there. With a lot of effort and in good cooperation with four caving clubs in the region we finally got permission on the condition that we would provide them with cartography. The tunnels are really gigantic and the water is about the clearest I have ever seen outside of Mexico. The main tunnel ends in one of the largest underground halls in France and we discovered kilometers of side tunnels. The idea that you are somewhere, where no one has ever been and your light is the first to shine there… That remains really special. The cooperation with the locals, who get to work with our data and film footage to find dry access to places that we have discovered, also makes it a very special adventure. 

What is the purpose of these cave dives? How extreme is this exploration?

The cartography we produced was used by the municipality to know where they need to protect the groundwater. The collaboration between science and cave exploration does add an extra dimension to your time underwater. You are not just swimming through a tunnel, but really contributing to something. The cave itself was not exactly easy: first you have to get all your stuff to the entrance, then you have to walk a long way through narrow, vertical tunnels with all your stuff and then you have five kilometers of underwater tunnels at your disposal that stretch in several directions like a kind of gigantic spider web. In some places the tunnels go up to 97 meters deep and are easily ten meters wide and 20 meters high. However, it only really gets exciting when, after a dive where you have been at a depth of almost 100 meters for a while, you have to ascend again and decompress to enter the cave... and then do some serious sport climbing and clambering over blocks as big as houses and finally do the same dive again to a depth of almost 100 meters to get out again.

You can't do a dive like that with just a few tanks. What kind of equipment should I think of?

We dive with KISS Classic CCRs (closed system rebreathers) with heliox 10 or trimix 10/70 as diluent (10% oxygen, 70% helium). The OC bailout in case the rebreather stops consists of two 20 liter bottles with Heliox12 or a sidemount bailout rebreather (the SMIR). Furthermore, we have placed several bailout bottles in the cave with decompression gas (17/75 at 75 meters, 35/25 at 36 meters, 50/25 at 21 meters and pure oxygen at 6 meters). In addition, we dive with the Twin from Carbon Scooter, a double scooter and we all have a Kevlar drysuit and suit heating in combination with dropweights - so that you become heavier and can therefore blow more gas into your suit - to be able to spend the hours of decompression in a somewhat comfortable way.

How do you map a cave? There is no light, how do you navigate in a cave?

In order to navigate in a cave, and to find your way back if your lamp breaks, we lay lines. You can then measure those lines again to make a map. The survey was partly done by hand. Knots that are in your line every three meters counted, partly with an MNemo electronic line measuring instrument and partly with a Seacraft ENC3 electronic scooter compass. We measured the dry spaces with a DistoX laser distance meter adapted for caving. Furthermore, we used special radio transmitters developed by Daniel Chailloux, both in the dry spaces and under water. He is the great cave survey guru of France. They transmit a signal through the rock that can be picked up on the surface and measured very accurately. So that we knew for sure that our data was really correct. The (extra powerful) transmitter for dry spaces must of course also be able to be transported dry in a dry tube made from the body of an old Gavin scooter. For communication with the surface there was a Cavelink, a device with which we could send a kind of SMS messages through a kilometer of rock, which made cooperation with the survey teams on the surface possible. Ultimately, all the data goes into special software – Therion in our case – and that software turns it into a map.

The extreme depth, the duration of the dives… does it always go well? You have little margin for error I think? 

Things always go wrong with this kind of diving. It can be small or big. Think of simply forgetting or losing critical equipment. Getting lost in dust clouds, getting separated, getting caught in loose floating lines, failing lights, collapses, leaking drysuits, scooter breakdowns, failing rebreathers… you name it. It happens and everything in this list actually happened during this project. When something goes wrong, you always fall back on your basics first: trim, buoyancy and communication. Just to keep calm and not make the situation worse. You always have more than enough gas anyway, so there is plenty of time to solve any problem. If you can't solve it on your own, you have your buddies to assist. It always comes down to: stop, stabilize, solve the problem, communicate with the team, find the line and turn around to go outside. We carry such enormous amounts of gas that you will always get outside as long as you keep a cool head and don't do stupid things. 

The type of dives you do were previously almost unthinkable. What has changed, improved, that these types of expeditions are now possible and also safe? The training? The exploration techniques? Or equipment?

Everything you mention, really. Developments are going so fast. What was the absolute limit of what was humanly possible thirty years ago, has now become just a nice warm-up dive. The most extreme dives of twenty years ago are now done regularly and the records of ten years ago have, with some planning, become beautiful, challenging projects today. The developments in the field of scooters, lithium, lamps, dry suits, cameras... it is really gigantic. The impact of standardization in equipment, training and procedures makes teamwork much easier and more effective. Where fifteen years ago you often had to hear nonsense like: "“Diving with a buddy only makes my dive more dangerous”, is that a statement I rarely hear anymore. And when I do hear it, it is actually justified because of things like extremely complex logistics, restrictions or dusty passages in which you can indeed do little for each other. 

What can a sports diver – open water diver – learn from these types of complex dives?

Besides learning from the equipment, skills and procedures used in technical diving, I would mention standardization and teamwork. Basically everything when I read it back. That is not so strange. In cave diving we focus on optimizing equipment and procedures for safety and efficiency. Why would you not pursue that in recreational diving as well? I honestly do not know of a better configuration of a diving equipment for say 90% of all recreational and technical diving on open circuit than a Hogarthian (DIR) setup. 

Of course there are exceptions, such as for people with disabilities and for tight passages, but as a basic rule, no one has ever shown me anything better. There is simply no simpler, more solid, more flexible, more streamlined, more thoughtful and safer way to configure your dive gear. 

Furthermore, I simply do not understand the limited attention paid to things like trim, buoyancy, swimming strokes, communication and teamwork in recreational training. The emphasis of many training courses is still on making an infinite number of ascents. As if the only solution to a problem is to flee to the surface as quickly as possible and fighting panic. Why do we not teach students that you want to solve problems underwater and that surfacing is a last resort. Why do we still teach so many skills while kneeling in the mud? Why is a regulator dragging through the mud still the standard way of donating gas to a buddy in need instead of the infinitely better backup and longhose solution that we use in technical diving? Why is the use of Nitrox still not a fixed part of basic training, but does this require additional training? Why do whole tribes of people still dive around with such a ridiculous snorkel on their diving mask or connected to each other with a buddy line? The PADI sidemount manual even mentions the use of a snorkel… a snorkel… in a sidemount course… sidemount… you know… that CAVE diving gear… isn’t that just completely bizarre? Don’t get me wrong, there have been many improvements, but there is still a lot to improve. 

Your topic on Duikvaker is 'The lessons we can learn from cave diving'.

What have you personally learned from cave diving?

In diving we've talked about that a bit, I think it's made me a much better diver. In daily life and work I notice that I also often fall back on things like: “stop, stabilize and check your line” when things seem difficult and are threatening to get out of hand. I think I have become more focused than before on directly and step by step dissecting and solving problems as they arise rather than dwelling endlessly and aggrievedly on the question why “this is happening to me again” and who I can blame for my own failures. 

Can you already give us a sneak preview of your presentation at Duikvaker? What can I expect as a visitor? 

I learned that adventure is right in front of (or under) our feet; caves are the last places on earth, or even the universe, that cannot (yet) be explored by robots. To see beautiful and unique things, you don't have to leave this planet at all, a car ride to the Ardennes is enough, as long as you know what you're doing and are willing to invest the time and effort.