Photos by: Laurent Miroult, Florian Launette, Patrice Cabanel, Franck Gentilli, Alexandre Legrix, Piovano, DR. 


Minus 260 meters underwater: my eye discomfort finally stops; I see clearly! A quick point: I feel conscious and decide to continue moving forward by pulling my guideline. A vertical shaft appears and the gallery continues to descend. Even deeper... The tunnel of scoriaceous rock is vast and lost in the dark. I'm the first man here. Alone. I slip into the blue night. The only landmarks are the roar of my breathing, through the filters of my rebreather and the propeller’s motor. I feel good. Extraordinarily lucid.

I anchor the wire on a stone spoiler, hands trembling with excitement but also with symptoms of “HPNS”, the dreaded high pressure nervous syndrome. I continue on my way a little, free, in the immense aquatic clarity. In the other world... Until a bed of sand wrinkled by the current. The continuation is ahead, at the back of a large room below. A look at the timer: 400 minutes of decompression... Fred, it's time to go home! I am 50 years old. I am at a depth of 308 m. A new world record. But I don't know it yet: more than with numbers, I dive first into sensations. Looking forward…


Almost a sleepless night. I slept little but I dreamed. These images... Nothing really new: for at least two weeks, I have spent my nights repeating gesture by gesture, second by second, this dive; to live on credit in the deep darkness; to optimize each control of the instruments, of the rebreathers, to roll in the distant gallery that I imagine the yellow guideline so precious...

Under the blue surface, in the calm and transparent water, green algae undulate which reveal the current coming out from under the earth. Where does this mysterious river come from?

While preparing my equipment at the edge of the spring, with a false cheerfulness of circumstance, I chat with the old dinosaurs of deep diving who have come to assist me. We talk about the heavy open circuit diving operations with these dozens of tanks which were the rule a few years ago and which required days of preparation whereas now I manage all this in 20 minutes!

I remember the previous months. From my endurance races in the Calanques of Marseille; these hours of breathlessness on the slopes, these kilometers traveled in the pine forests, the scrubland, the rolling limestone scree; always... Dozens of deep training dives also, right here, in these warm waters of the Catalan country, down to the -260m zone; to familiarize myself with the topography of the place, with this flooded gallery of more than a kilometer; to acclimatize the body and the mind too, perhaps... To fine-tune my decompression curve as precisely as possible: obtain a minimum diving time without risking an accident underwater. Adapt by small successive touches, in real size, the nature and positioning of my equipment; blend in as best I can with the environment; let his hostility become mine. But, without me really being aware of it, my body had already decided to venture into the unknown, beyond -300 m...


The thrusters and rebreathers are in the water. The timers set to the minute with the divers who must meet me at the decompression stops, at -120m, there... Heated underwear, drysuit... I get help to close it and I finish adjusting my equipment in the basin, water halfway through the body. Harnesses, fins, rebreathers, with the same ritual of recent months: don't forget anything, it will go very quickly. All this equipment must respond to my requests instantly. Mask ! My precious ; so essential... I rinse it, adjust it carefully and... off we go.

The aquatic horizon is blue, streaked by sunlight... A black porch opens into the gray rock. I go down into the vertical shaft that follows it and let myself be swallowed up by the night. Balancing of the ears, drysuit placed on the body, lungs of the rebreathers emptying, hissing of the inflators: The battle against pressure is on!
The DPV is now taking me into the drowned gallery at more than fifty meters per minute. I take the opportunity to have a look on the rebreather displays to check the partial pressure of Oxygen of the mixture I am breathing, essential data. I will never take my eyes off these indicators; it is the only solution to avoid poisoning myself.


My ship's cruising speed is stable. A Seacraft scooter in front which tows me and another attached as a backup to my back. My headlights go far, the water is very clear, the walls pass by. The automatic control of my instruments is established. I navigate above the guide cord installed in the main gallery, under the corbelled arches tinted with iron and manganese oxides; rusts, browns, yellow ochres, deep blacks, red clays; eroded mineral architectures, sharp as razors, crossroads of secondary galleries or even the direction of the current sometimes plays tricks on us: Font Estramar is a complex labyrinth of corridors and dead ends where you must not get lost... I'm waiting a bit of Patrice Cabanel following me, riding his double propeller. He passes me at full speed and goes much lower in the large vertical well to make a few videos as I pass.


Minus 200ft / 60m. The actual diving will begin for me. Final checks before the big jump: it's time to turn on the powerful headlights and start up all the equipment that will be blocked by the pressure in the deep zone. It’s the last reasonable moment before the big night that’s about to arrive… I have to get ready and jump!


At 328 ft / 100m I arrive at Patrice who is waiting for me, camera in hand. And he follows me downhill! – 492ft / 150m, 557ft / 170m: let's race! Quickly. Too fast. Like two bikers launched on a vertical track and I don't know who is the more carefree of the two in this story... He is still in my wheel but the maximum test depth of his scooters becomes critical... 590ft / 180m. I have to stop him: I don't want his vehicle to implode under him in the heat of the moment! And I remember this Finnish diver who was torn apart by his scooter and for whom I had come to assess the circumstances of the accident at the request of the French authorities. His body is still present in the cavity which is today his tomb, protected by more than 656ft / 200 meters of water. I continue the descent, crazy organ music filling my head.

And, as Patrice Cabanel will tell it: “What for Fred is only a little more than half of his journey represents for me a giant step. Here I am at a depth of 624ft / 190m and I watch it sink even further. Surreal vision of seeing it exceed 656ft / 200m and disappear from sight”...


The further I go down, the lighter the rock becomes. The geological layer has changed: I go back in time. I will reach the horizontal section of the tunnel which oscillates between 820ft / 250m and 853ft / 260m depth. A place that I know well having visited it many times during my training. A round trip usually costs me one hour more decompression, but today, I know it will be much more because I am going to go further.

Arriving at the bottom of the well, at 853ft / 260m, I stand up and am then overcome by a strange discomfort that I have never experienced: a dazzle; the floor of the horizontal submerged gallery seems to be flooded a second time; it’s like a backlit sea, agitated with reflections. I move forward as if in a dream; disoriented…

In the professional environment, a compression at 984ft / 300m considered “quick” is done in… 24 hours! But there are problems linked to compression in a bell or a diving box, in particular the heating of the gas which must be allowed to cool. Problems that a scuba diver underwater does not have. But today it's no longer training and the little run in the well with Patrice increased my usual descent speed. Maybe I'm paying the bill for it now.


The discomfort ceases as it came and I regain my sight. My horizontal journey to the lip of the terminal shaft seems to have put me back in shape. Ahead, a black abyss. No more guideline! I have to connect my own reel and secure the line securely. My hands are shaking... The SNHP. It’s an obligatory appointment and one that no longer surprises me over time, after already more than 12 years of deep dives below the 656ft / 200m mark.


I no longer count: I am in ecstasy. The moment we have been waiting for more than 6 months - or 20 years? - has arrived. Low speed, the yellow wire unwinds regularly and my “trim” is perfect. Balancing and positioning in the liquid environment is one of the keys to survival, to limit your physical efforts and therefore your metabolism. With wide eyes, I record the stranger passing by; the receding blue horizon. It is the show that punctuates and guides my progress, my gestures and decision-making. Now it is the exploration itself that motivates my diving. I slide down an increasingly wide room that sucks me in. On the way to my destiny.
More than 80ft / 25 meters of visibility! My vision is lost in the blue transparency, which turns black. It's majestic, truly majestic.

I keep an eye on my wire so that it doesn't get stuck when I return to a trap section - too narrow - of the gallery. I take advantage of my optimal mental state to record these magical moments that I have always imagined and which are mine today. Another splitting of the line on a sharp rock in the ground and I read astounded on my computer that I already have 400 minutes of decompression to do! Too short. It’s too short, I would really like to continue. I must force myself to tear myself away from the spells of unexplored depths. Hurry up. Every second counts at these depths. I decide to lock my reel and leave it there to mark my terminus. Little wink: it's that of Krzysztof Starnawski, another deep diver, who himself had abandoned at the bottom of the magnificent Cetina spring in Croatia and whom I had recovered there during my first.

I'm on my way to the distant surface. My recovery is rapid. I can't wait to tear myself away from the abyss and begin my decompression. It’s way too fast and I’m going to pay dearly for it but I don’t know that yet…


I’m coming early at the first stage of 426ft / 130m and I follow the deco stops. It is at -296ft / 90m that Bruno, support diver, finally joins me. At last, I can look at all my measuring instruments. And I discover the incredible depth that I have reached: minus 1010ft / 308m! Indeed, during these deep dives, I first monitor my condition, then the partial pressure of Oxygen. Then the “run time” - the diving time - and the expected duration of the stops. Depth is ultimately incidental… I don’t focus on it. If my body says yes, I'll go. I didn't suffer: it was really the constraint of decompression time that forced me to turn around.


We are swimming to the 262ft / 80m level. I suddenly experienced great difficulty breathing; blocked rib cage! My lungs feel clogged. My upper body feels like it’s locked in a cage. Gas poisoning? I quickly change the rebreather tip but nothing works. It’s not the toxicity of the gas: the problem is something else. I am afraid of this unknown but I live. In any case, any panic is prohibited. It’s wisdom and experience that must speak… I breathe “through my stomach”, like in training. Difficulty. Like through a straw. But, even if the ventilated volume is small, it is sufficient. The minutes pass... Bruno is there, with me. He will stay 4 hours watching me.

Worse still: I feel a sharp pain in my back. In addition to the breathing problems I suffer from an oppressive feeling, as if my suit was being crushed by the pressure; as if the metal plate of my harness weighed tons. This ordeal will last more than an hour. It's only when I reach the 100ft / 30 meter mark that the grip loosens and I finally feel liberated. I breathe. I am alive. I remember…

After the debriefing with Bernard Gardette, physiologist director of deep dives and extreme environments at Comex - the man behind the legendary deep dives where Théo Mavrostomos reached the depth of 2300ft / 701m - It seems that the visual illuminations that I experienced are one of the symptoms of SNHP. Just like tremors, more common. In any case, the range of numerous harmful effects of this neurological damage due to helium under pressure has been very little studied. Vomiting problems have also been reported. Still happy that this didn't happen to me underwater... These are annoying but reversible physical conditions and the intellect is not affected.

The respiratory oppression, on the other hand, seems to be due to a massive outgassing of helium due to my too rapid ascent. With an influx of circulating bubbles that I managed to eliminate little by little in the lungs but also with symptoms of spinal cord injury in the back and kidneys. The spinal cord… A risk of permanent paralysis…

It’s true, our computers are set to warn us if we rise too quickly. But I have always calculated and applied personal procedures and I have gotten into the habit of no longer heeding these warning bells. And I let them squeal. By moving my arm away. Who is the Boss ? I got used to their haunting music. Like the unmarried man at home who no longer hears his wife screaming...

Gardette will confirm to me that we can go up quite quickly from 984ft / 300m to 656ft / 200m but then we absolutely have to slow down before the first deep deco stop! Valuable data that I will take into account to adapt my next deep dive in the terminal well of the Mescla cave in the Var gorges.


Franck joined us in turn, at a depth of 164ft / 50m. It’s time to scribble a message that will be carried to other divers, higher up, and to the surface. A simple wet sheet of paper but which says a lot: "Fred 1010ft / 308m tt is OK"...

Many hours still separate me from the surface. I am doubly locked up: in the flooded gallery of course but also by this physiological limit which in any case prohibits me from going back directly under penalty of a serious or even fatal decompression accident.
I float. In a “degraded phase”, almost drowsy. It’s about adjusting my physiology to the vital minimum. Become one with water. Effortless. Listen to time expand. Dreaming of beyond...


I arrive at the bottom of the exit shaft and I see daylight from a long way away. I want to scream. At the 40ft / 12m level, new alert: I distinctly feel a loss of fluids, from the hip to the foot. The feeling of having urinated in my drysuit and it's such a realistic feeling that I have doubts! I move a little: my leg works. And I'm dry. But my “bladder” seems inexhaustible. Gardette will talk about “skin sensations”, a phenomenon of decompression without gravity.

30ft / 9m. The habitat ! I could finish my decompression there in the dry, sitting with my legs in the water. But I decided to do without it. In fact, it is a complete change of configuration: you would have to remove the equipement, change environment and position, accept having blood circulation partially obstructed. It's risky. Presently I am horizontal, in zero gravity, in a daze, perfectly lying down, and this seems preferable for good decompression. I float weightlessly, in my rock vessel. Happy. Almost comfortable.

I adjust my heating: Even if the slightly brackish water - memories of ancient seas - is rather warm, between 64º/66ºF 18/19°C, we risk getting cold. Because of the immobility but above all because of the current, which is stronger here: All the galleries of the fountain come together and all the water exits through this well and therefore the caloric loss is greater.

Life is here ! Curious eels come to add their flexible tubes to my equipment. Clouds of silver mullets dance in the sun. Minus 42ft / 6 meters. The draperies of filamentous algae slowly fray in the water theater. The tangled roots twist their lignite arms. The other side of the reed bed…
It’s time to eat my bottles of apricot compote – we’re in Catalan country! - and for me, who never eats sugar, it’s a real energy booster. I realize in passing that I am probably dehydrated. A bad point for decompression. I will have to remember to drink more during my next attempts.

I've been underwater for almost 7 hours. The helium gradually left my body; the air is there, very close. I see it, beyond the mirror of the surface. With all humility, I take stock of this new contribution to exploration. This is a big leap forward that will break many preconceived ideas. A paradigm shift for the future and for the entire community.

Our exploration activity has always benefited from previous achievements. I think back to all our elders, these pioneers who gradually reduced psychological barriers. This is a new milestone. Like a plank thrown into the swamp, to be able to move further. The great speleonauts had all done it. It was time for me to do it myself. I feel proud too. Of these moments of pure beauty that I experienced. Of these few dozen meters snatched from the unknown. And to be able to tell it.


I emerge. Lower my mask and my hood. Splashes, drops of silver, laughter; the noises from outside; smiles of friends. The smell of life...


My Equipment

Throughout my dives, I have selected and tested a whole range of equipment from the best europeans manufacturers. Above all, able to function and withstand the significant pressures of the depths where I operate (>300 m).

Thermal Insulation

Diving drysuit  Ursuit (Finland).
Heated underwear Santi (Poland). I regulate the heat provided by the Seacraft DPV batteries.


Thanks to the harness XDeep (Poland) and the “Sidemount” configuration of my rebreathers, I obtain perfect trim with a minimum of ballast. I dive without a buoy, using only the inflation of the drysuit for balancing. If unfortunately one of my rebreathers were flooded, making my weight negative and dangerous, I would just have to unhook it and leave it there.


2 closed circuit rebreathers (Czechia) worn sidemount. I breathe on the main (degraded), fixed on the left side, while regularly testing the backup (redundancy) on the right side. The latter is more flexible when breathing due to the position of the inspiratory lung, closer to the body. Filters modified in size, each allowing a duration of 9 hours in C02 purification. With an autonomy of 9/10 hours per rebreather.


Trimix 4/89 mixture (Oxygen, Helium, Nitrogen).


Each rebreather included 2 x 2 liter tanks (pure oxygen and diluent) to which I added a 2 liter tank of compressed air at 374 bars for inflating the suit  and another 2 liter tank of 4/89 diluent (off board) to compensate the too low autonomy of the big deep rebreather. Totally 6 tanks.


2 computers (Czechia), modified Buhlmann algorithms, independent and supportive of each rebreather.


2 scooters Seacraft Ghost (Poland). Pressure test >300 m. Multi-speed. More than 10 hours of operation for 30 km of autonomy. Also serves as a battery for heating. Supports main lighting and an inertial measurement console. Designed to operate coupled, I separated them, keeping one as a backup fixed behind me, so that I could have one hand free when navigating.


2 main lights of 50,000 lumens each attached to the front of the scooter. I am the designer and manufacturer of them with our brand Callisto (France).
1 front Phaeton (Greece) attached to the helmet. 10 hours of autonomy at 20W adjustable to be able to illuminate the near field, the hands during reel maneuvers (French technique)...
1 light Tillytec (Germany) fixed on the arm: 2 h at 4200 lumens.

Images and datas

Navigation console ENC 3 Seacraft (Poland). It is an inertial unit which allows the position in space to be recorded, coupled with a “loch top” as in sailing, a small propeller allowing the displacement to be recorded.
Camera housing Isotta (Italy) worn on the head.


Several tools and cutters.
Harness and buckles.
Fins, emergency equipment (mask, etc.), lighting and comfort.


Individual deco bell installed at - 9 m. Scalable up to - 6 m. Fixed by cables on the bottom with ballast or bolts (expansion bolts). Sitting position, legs in the water. Homemade. 2x4 hours of oxygen autonomy per open circuit cylinders.


Gas mixtures and consumption.

Mix type: I use Trimix. For this dive, 4/89 that I prepare myself. Why Trimix rather than Heliox? I did some tests but the Trimix is ​​much more “comfortable”. In addition, the presence of nitrogen in the mixture would limit SNHP (high pressure nervous syndrome) thanks to the narcotic effect of nitrogen. I use a low percentage in mixtures (between 7 and 10%) to avoid narcosis and limit nitrogen saturation. For this dive, the compressed air nitrogen equivalence corresponded to - 30 m. The isothermal performance is also better.

What about the use of Hydrogen as a diluent in deep diving? The Australian Richard Harris successfully tested it while exploring the Pearse River in New Zealand. It’s innovative and maybe it’s the future? We are indeed “test divers”. But there is not enough perspective on decompression. According to Bernard Gardette of Comex, who had successfully completed the first very deep dives with this gas, the decompression algorithms for Hydrogen are modeled on those used for Helium and this would therefore bring nothing in terms of diving time.

Above all, there is a serious safety problem: mixed with Oxygen, Hydrogen risks reacting explosively to produce… water! It’s an unstable mixture that requires rigorous industrial procedures: You can’t do that in your garden…

Making of mixtures: Starting from B50 industrial bottles of pure gas with the usual procedures. First I transfer the Oxygen, then the Helium then I add air. At all times I check the O2 level with several instruments and my spreadsheets. Next comes the overpressure procedure to fill the diving tanks with a booster MPS Technology 380 bars, an Italian company that has been following me for a long time.

Gas recycling and decarbonization: 2 sidemount rebreathers with 3 kg “Sofnolime” filters. I had to change the size of the original filters to much larger models because of the depths reached. Otherwise, the gas risks not having time to travel through the loop correctly: I risk breathing unfiltered gas and getting CO2 poisoning! I was inspired by what the US military had developed for their dives beyond 200 m. Comex safety rebreathers too… With of course implications in terms of respiratory comfort and weighing. I had to acclimatize myself and adapt my technique accordingly.
Note that the descent is so rapid that I directly breathe the 4/89 that I inject. The recycler then functions like a regulator: the gas does not really have time to circulate in the loop.

Oxygen Control: These are electronic rebreathers but deactivated: During the dive, I manually control the partial pressure of Oxygen constantly. I am more “oxygenated” than in the open air but I chose, unlike many, to dive with a very low oxygen level, even at the stops (pp O2 < 1.6). Above all, I fear hyperoxia. On the computer I can read the potential toxicity of the mixture. Depending on this, I inject or not the diluent or the Oxygen. It's like a stab inflator, very practical: Right Oxy, left Mix.

Decompression: The computers work with traditional Bulhman algorithms. Connected to the rebreather, they monitor the gas I breathe in real time. And calculate a theoretical decompression from the depth of -50 where the countdown begins for this kind of cave profile. To reduce decompression times, in addition to personal procedures based on my experience and my physiology, I adopted a Gradient Factor of 80/80 which is quite committed. I am indeed close to the maximum desaturation curve (at 80%). Usually we follow a GF of 50/80... Following the findings of this last dive and to prepare for future attempts, Bernard Gardette also sent me new curves adapted to my physiology.

Consumption: As can be seen in the various data tables, during this 7 hour dive to -308 m, I only consumed 850 liters of Trimix 4/89 diluent and 486 liters of pure oxygen. Or an average of 0.4 l/min of Oxygen, including the numerous rinses. An extremely low metabolism…


Physical and mental preparation for this type of diving

Over the course of our attempts, we gradually abandoned the notion of “mixed redundancy” by transporting “bail-out” bottles in an open circuit. It's useless at these depths because it's too heavy! In an open circuit, for this type of diving, it would have been necessary to carry 25 to 35 kg of various gases, the equivalent of 10 bottles of 20 l to 200 b for a weight of more than 200 kg... In addition, a classic regulator does not work properly at these depths: The required flow rates are far too high.

Which means that it is necessary to develop a psychological adaptation to the potential risks of breakdown on the main rebreather. Hence the use of a second redundant recycler. We therefore completely switched from open circuit technique to closed circuit technique. Which surprises all divers of the older generation, accustomed to “assisted” breathing. Indeed, the regulators, without us being aware of it, are very flexible when inhaling, which triggers an influx of gas at positive pressure. With rebreathers it's different: It's our lungs that decide and it takes both physical and psychological training to be able to ventilate effectively. We must control our breathing rhythms, our consumption, our metabolism. And above all, do not allow yourself to be drawn into the effort zone, otherwise you will experience uncontrollable and often fatal shortness of breath. You have to acquire the strength to ventilate yourself for a long time. I have experience diving for more than 15 hours with this type of mixture and equipment.

My goal is to be as light as possible. The most hydrodynamic. To get to the point. To be able to progress underwater quickly and without excessive and unnecessary fatigue. In full possession of my means without superfluous accessories that could influence my psychological state. So I gave up the pressure gauges on my tanks as I am so fine-tuned to knowledge acquired during my training and development dives. I know exactly what I am consuming. A kind of “alpine technique” adapted to deep sump exploration..

It was on the initiative of Professor Petit, Director of the Arago Laboratory in Banyuls-sur-Mer that on August 27, 1949, two officers of the 11th BPC (Shock Parachute Battalion): Lieutenant Dupas and Lieutenant George, dived into the abyss, equipped with the Cousteau-Gagnan autonomous diving apparatus. They dove through an entrance in the form of a porch about four meters below the surface, at the very foot of the cliff which overlooks the basin. From there, they progress into a vertical shaft approximately six meters high, opening into a large, totally submerged room 45ft / 14 meters from where two opposing galleries appear to branch off, one towards the south and the other towards the north. Noting that these galleries continue to sink inexorably into the mountain, the divers prefer not to explore further and decide to go back up for lack of more suitable equipment.

Followed by the expeditions carried out in 1951 by Cousteau, Tazieff and other great divers... Several secondary galleries were explored around the main conduit. The depth reached in 1955 was 164ft / 50 meters, the techniques of the time not allowing it to go any lower.

In the 1970s, Claude Touloumdjian explored a total of 2788ft / 850 meters of galleries in several branches of the network. In 1981, Francis Le Guen advanced in the main conduit to the Well of Silence (410 m) and explored it down to 190ft / 58 m.

In 1991, the ARFE (Research Association of Font Estramar) was created and the depth of 538ft / 164 m was reached on August 15, 1997 by the Swiss Cyrille Brandt. Pascal Bernabé continued to 603ft / 184 m on June 4, 2006. Jordi Yherla, a Catalan diver, descended to 626ft / 191 m without finding a continuation of the sump, in July 2013.

On August 16, 2013, Xavier Méniscus, equipped with a double rebreather and helped by a large international team, continued the exploration of the cavity in the giant Loukoum well located 1683ft / 513 meters from the entrance, to a depth of 814ft / 248 meters (2952 ft / 900 m from the start), bringing the development of the cavity to approximately 9514ft / 2,900 meters.

In July 2015, the same diver, with the help of around fifteen team members, pushed back the exploration by around thirty meters to a depth of 859ft / 262 meters.

In June 2019, Xavier Méniscus continued his exploration over a distance of 164ft / 50 m horizontally to a depth of 859ft / 262 meters to reach the lip of a vertical well.

After these three explorations, on December 30, 2019 Xavier Méniscus descended to 938ft / 286 meters in the bowels of Font Estramar, at a distance of 3346ft / 1,020 m from the entrance.

On November 3, 2023, Marseille diver Frédéric Swierczynski reached the depth of 1010ft / 308 meters, a new world record, during a 6.59 hours dive. Stopping in front of the void after pulling 229 ft / 70 meters of line...


The hydrogeology of Font Estramar

Font Estramar (or Rigole’s spring) takes its name from “Font Extrema”, in reference to its location at the extreme limit of the territory of the commune of Salses-le-Château (Oriental Pyrenees). It springs out at the foot of a small cliff, at the edge of the highway. An escarpment of tectonic origin, on the edge of a plateau nearly 200 m high, in massive limestones of Urgonian (Barremo-Aptian) facies.

It drains jointly with Font Dame the karst system of Corbières d'Opoul and the Bas-Agly syncline and receives the losses from the Agly and Verdouble rivers. It constitutes the main supply of fresh water to the Salses-Leucate pond. The karst system is also connected with the Plio-Quaternary aquifer, an important water resource for the Perpignan region. The flow of the resurgence is used downstream of the basin by a fish farm before reaching the sea.

Font-Dame is a sub-lacustrine source, formed by eight emissive cracks hidden by a floating phragmites marsh (exploited reed bed). Both are important Vauclusian springs with a low flow rate of 1.5 m3/s for Font Estramar and 2 m3/s for Font-Dame. Other springs mark the same tectonic contact: the temporary exsurgence of the Malpas, and emergences through the alluvium, in the Salses plain. The whole represents the outlets of the karst hydrosystem of the south-eastern Corbières.

The water is slightly brackish, probably due to the intrusion of deep salty wedges coming from the Leucate pond and the sea. Indeed, in the Upper Miocene, during the “Messinian crisis”, there are more than 5 million years ago, the evaporation and regression of the Mediterranean Sea to a depth of more than 1000 m led to strong karstification below current sea level (at -300 / -400 m). Constant temperature throughout the year: 17.8°C.


A cursed spring?

Due to numerous accidents, Font Estramar has a very bad reputation as an “accident-prone” cavity. Already in July 1955, during a television shoot with Haroun Tazieff, diver Jean-Claude Guiter lost his way in an annex of the south gallery and died there. A plaque on the cliff commemorates this death which will mark the spirits. This fatal accident justified a temporary ban on diving. The diver not having been found, the portion of the gallery where his body was supposed to rest was blocked. It was only in 1958 that his body was seen by André Bonneau, stuck in a chimney.

Another Czech diver died in Font Estramar in May 2008. On this occasion, the source gained its sinister reputation as a “killer sinkhole” when this was not the case, in fact. A labyrinthine maze, certainly, and deep but no more dangerous than many lesser known, and therefore less frequented, drowned caves. This resurgence is the only site in the area, so more divers go there. But there are more people dying on the beaches, or in the mountains, than here... The problem is that it's unknown. Exploratory cave diving is a specialized discipline, which requires specific and rigorous training and techniques under penalty of death.

As Frédéric reminds us: “It is a shame that the Pyrénées-Orientales does not do like other French departments. The Lot, for example, is the number one destination in Europe and attracts divers from all over the world; an incredible economic windfall. The department took the lead: they did everything necessary to welcome the divers. It is time for things to be done the same way in Font Estramar.”

But the popularity of this Catalan source only continues to grow and the black series continues. On May 24, 2012, a specialist of the place, the Gruissanais Jean-Luc Armengaud lost his life there. We also recorded, on January 23, 2016, the death of a Sète diver in his fifties, then on June 10, 2017 the death of a 44-year-old Finn whose body was found far beyond - 200 m by Frédéric Swierczynski. Belgian stuntman Marc Sluszny in turn disappeared in a diving accident on June 28, 2018. The following July 9, Laurent Rouchette, a cave diver from Spéléo Secours Français, died during the search for the body. Finally, on July 19, 2023, an experienced diver from Puy-de-Dôme, aged 63, lost his life while returning to the surface.


From left to right: Ugo Tonolini, Bruno Gaidan, Yvan Dricot, Michel Ruiz, Frédéric Swierczynski, Franck Gentili, Christian Deit. Out of field: Christophe Imbernon, Patrice Cabanel.


Acknowledgments - Partners

Comex SAS - Phymarex - Beuchat - Seacraft - Isotta Housings
MPS Technology - Plongimage - Ursuit - Vertical Adventure
Eurodifroid - Xdeep - Custom Diving Systems -
Damian Jakubik - Witold Hoffmann - Alpha Requalification
Santi Diving - Georges Ruggeri - Olivier Bertieaux
Elisa Isolde - Manlio Pagotto - Nina Katia Ferro - Lucie Šmejkalová
Komninos Boutaras - Jakub Slama - Mathieu Coulange - Bernard Gardette - Olivier Isler - Cyril Brants - Richard Harris
Nuno Gomes - Krzysztof Starnawski - Luigi Casati
Laurent Miroult - Alexandre Legrix - Severi Rouvali