Since 2003, the Doubs has begun my mecca of sumps. Here, one can find many sumps that are tough, difficult, without being very deep. In addition, the weather and the landscape are less attractive for the category of cave divers who want to do technical diving underground, so I have found a stillness impossible to find in more southern regions such as Lot. This isn’t only a matter of sumps and caves. Very simply, Nathalie and I feel at ease here. People are kind and keen. After we have buy a barn during the spring of 2004, we never have been despised by our neighbours as in Paris region.
After the initiator training session, I had been advised to have a look at the Combe du Creux. Viewed from outside, the sump is a pond that lies hidden in a wood, near green meadows in a shallow valley (Pictures 7.1 to 7.4). This is really a pretty place; with a blue sky and sun shafts, it is an invitation to wilderness. The men who dived this cave before I came have made a great job. They have put a ladder in the pond in order to facilitate the descent with heavy tanks. Otherwise, when the water level is low, step slipping in the sand, mud and gravels would be very painful. The risk of being trapped below would be real! They have enlarged a part of the entrance, which was quite narrow. They have laid a thick rope up to the deep horizontal part of the cave. This rope renders decompression stops safer in case of buoyancy problem. Last but not the least, they have laid a guideline and explored the cave up to a fork at about 400 metres from the entrance. The right fork had been explored by them up to moving mud dunes, and the left fork had not been explored.
The first time I went near the cave was 14 September 2003 with Didier, the leader of the initiator training session who was also one of the former explorers. He has been very kind with me and has even helped me to carry some pieces of material. I wasn’t very at ease with such help. Cave divers are by no means superior to other men, and the limit between kindness (it was the case) and deference (it is the case of most people) is thin. What follows is issued from my diary:
I found intact the rope he has laid in 1994. The descent is a succession of steps as Didier explained me. Near its entrance, this cave is quite complex and has probably had a complex story. Especially, there is an impenetrable passage that leads back to the entrance, below the heap of blocks that lies at the bottom of the pond. This passage was lighted by some sun shafts, so it appeared very beautiful as well as very hazardous. After the entrance, the passages are wider. In some places, I encountered a cloudy, milky water, and I have been obliged to turn off one of my lamps. It was too powerful, and the light was too diffused. The depth increased quickly, and I had the surprise to reach -20 metres, having virtually consumed no air. I found a big step. This is a flooded pit that leads to the deep zone. According to what Didier told me, its top also reaches the free surface. I thoroughly verified the rope, looked at the passage and swam down. I arrived to the place where the rope stops, leaving a place to a thinner guideline. A tag that indicated 110 metres was still clearly visible. I stopped at the depth of -50 metres and went back. I did not know the cave and had just two 9l tanks and a wet suit. I was obliged to do some decompression stops in the ten-degree-Celsius water; meanwhile, Didier and one of his sons were outside, waiting for me.
I was still shattered by what happened few months ago in Mexico, and I had also the fear I described. Below in my diary, I have also found the following notes:
I was far from the problems I had encountered. Very often, in this cave as well as in other caves of the Doubs, reflections of this kind have arisen in my mind. Healing takes a very long time.
12 October 2003
I am weary because of my job, and I need some mental rest in this sump. The road along the River Doubs between the towns of Beaume les Dames and L’Isle sur le Doubs is beautiful. We are in a season where light is lower and leaves have warmer colours. The water level was one metre higher than during September, and the pond appeared quite opaque. I started with two 12-litre tanks, a 9-litre stage tank and an oxygen tank for the decompression. After entering the cave, I found a part of Didier’s rope replaced by a piece of new dark and green rope with very pedantic eight knots. Who? Why?
During the progression, the visibility was limited. However, I was able to see the guideline, my hands, and a part of the walls. Mud has begun to sediment on the rubber bands I let in September, and there were no traces of those who have installed the new rope. I breathed pure oxygen up to -6 metres after what I closed the tank and let it fixed on the guideline with a screw-less carabiner. I put the other tank at the beginning of the depth zone after what moving has been easier. In addition, in case of problem, this tank had provided a good safety margin regarding decompression stops. I progressed along a double guideline: its two strands were close to each other, only one has flags. I didn’t know very well the cave, so I stopped before having consumed all what would be theoretically possible. My back tanks were full of a mix with 26% oxygen. There is less nitrogen, and at a depth of 50 metres, this is also a limit regarding the toxicity of oxygen. I suffered any narcosis, and my immediate feeling after diving has been ‘doing some première in this cave would be especially interesting. Even simply reaching its actual terminus would be a valuable goal’.
From a geological point of view, it seems that this cave has not always been flooded. One can see some concretions underwater at about -4 metres.
14 April 2004
I got entangled in the deep part of the sump, but I succeeded to solve clearly and quickly the problem. Of course, I have not used the pedantic methods described in some papers. Just after this dive, I went to the notary’s in order to sign in and buy this barn we want.
15 April 2004
I got breathless in the deep part of the sump, but I succeeded to solve the problem. Very probably, narcosis can explain this problem. Perhaps some remembrances of the Mexico have enhanced this problem? Or perhaps is it due to the barn and what it changes in our lives?
We took a weekend during June in order to reorganise my flat in Paris’ Region. It was necessary but very painful. Before we can move and live in our barn, I needed to sort out the mess of all my caving materials. Nathalie was so tired that she had a car accident on the motorway the next Monday. Years later, I still regret this situation because on my side it was egoistic.
10 July 2004
I dove in order to prepare the incursion of tomorrow. I put an oxygen tank at the right place.
11 July 2004
I laid guideline in the passage at right after the fork until the passage became too narrow and too muddy. Then I stopped, went back and laid guideline in the other passage at left. I have stopped because of the runtime and the decompression to do, but I have surveyed the cave when coming back.
Forty-five minutes have been spent in the deep zone, with a consumption rate lower than 13 litres per minute. The consumption rate was lower than 14 litres per minute for the stage tank and lower than 13 litres per minute for the oxygen tank.
20 July 2004
I wanted to try a model of rebreather for further decompressions in the Combe du Creux, but it is not reliable enough, and it leaks. I have to improve the reliability and render it more handsome. This is by far more important than oxygen sensors, blinking LEDs or any possible embedded electronics that seduce all the rivals.
31 July 2004
My father has had important health problems on 20 July, and he has lost a leg. This is a catastrophe for him, for my mother and for our small family. I have moved and visited him to Nice’s hospital. During more than a week, I was unable to do caving because of that… . I have stopped the dive at 420 metres from the entrance in the left branch. My consumption was higher than the last dive but lower than the standard 18 litres per minute. Regarding further dives, I will be obliged to add one stage tank or perhaps two if I am obliged by the size of the passage to use 12 litres main tanks at place of the 18l. It will become a siege.
23 August 2004
I dove with a wet suit and two 12-litre tanks. I wanted to explore what I believed a passage starting at the beginning of the deep zone, but this is just a part of the main passage partly filled by pebbles. I explored another passage that starts at the place where -6-metre oxygen decompression stops are done. It is not very wide, not very clear. After 15 metres, I stopped and fixed the guideline on blocks, perhaps in the bottom of an ascending shaft. It is difficult to be more precise; the visibility had become very poor.
1 November 2004
The pond has risen, and a small brook flows outside. The fields are wet. I hope the water level will decrease before the incursion planned for November 13.
12 November 2004
I dived in order to install two oxygen tanks and also one stage tank at the beginning of the deep zone. The consumption has been lower than 14 litres per minute. I had thick underclothes in my dry suit, and I felt more at ease without narcosis… . I feel a great happiness: Nathalie and I are together in the Doubs. Moreover, I am very happy to dive alone, which means without anybody from any club or official institution.
13 November 2004
I have used two 18-litre tanks, one 12-litre stage tank full of air, one 7.5-litre stage tank full of 45% oxygen gas mix, and two oxygen tanks. The consumption was still low, less than 14 litres per minute and even less than 8 litres per minute during the decompression stops. The temperature was ten degrees Celsius.
I laid guideline up to 480 metres from the entrance and succeeded to pass a clay dune. I stopped at a depth of -39 metres because of the autonomy and because of the fact I have consumed too much guideline. The last metres I have laid are devoid of any label, for they belonged to the safety core of my reel. The perhaps last 30 metres are too close from the axis of the reel to be efficiently rewind. Ordinarily, I try to keep them in case of problem, for instance to solve an entanglement. I spent 160 minutes in the sump. Due to the stage tank, I moved in the deep zone only to a mean speed of 14 metres per minute.
Perhaps two hours after the end of the dive, I felt bad. I saw very strange phosphenes. I don’t believe it was decompression sickness unless it was something very strange and delayed. Was it what doctors call a foramen ovale with micro-bubbles reaching the brain? But in that case, why not just after diving? Another possible explanation is that I was dehydrated and hungry. A third possible explanation (due to the fact I breathed very slowly during the oxygen decompression stop) is that a kind of delayed hyperoxic incident happened. Anyway, I lay down with legs higher than head and took aspirin. Nathalie was slightly anxious, but she has rehydrated me with many glasses of Adelscott. This is a beer made with smoked whiskey malt and which contains not too much alcohol. This strange ‘medicine’ has had good moral effects. Less than an hour after, I had fully recovered. The phosphenes had disappeared, and I got no other problem.
After this dive, I have realised that I was beyond all was expected or could be accepted by all those cave diving commissions. I have also realised that despising certain persons was giving them a supplementary space and enhanced their existence. I just had to forget them. Even regarding close relatives, I have to be stealthier, for I no longer want that one speaks about what I did or failed to do. I was (and I am still) by far less interested by a reputation than by doing the caving I want to do. Very probably, if I earned money with this activity, I would be obliged to have another behaviour. Anyway, life cannot be rewound and lived again; this is a meaningless question.
I had got entangled with the guideline, and I had solved the problem. I had also had other problems with guideline in other caves. I have always solved the problems in another fashion than the academic one, especially the two techniques that were or are taught during training sessions. I don’t want to give their description here, and readers interested in technical details will find them in the following online French review: http://www.calameo.com/books/000534681815b81338a2b.
According to my own experience, I think they are not always efficient in real conditions, and I wish develop my point of view.
The first of these techniques is the one devoted to solve entanglements. From a theoretical point of view, it works perfectly even without visibility if one is entangled with one’s own guideline. However, it is based upon hypotheses that are not always realistic. For instance, it doesn’t take into account the following situations. Firstly, it can happen that one follows a guideline and one gets entangled with another close guideline. The strict application of the methodology would lead to mixing up your guideline and the other and to getting lost. Secondly, it can also happen that in a flat and narrow section of a cave, one gets entangled without being able to reach the guideline. Then the method just cannot be used.
The second of these techniques is devoted to finding back the guideline when one got lost. From a theoretical point of view, again, it works perfectly even without visibility. Practically, this technique does not take into account the case where many guidelines exist in the same passage. Once caught, which is the right one? What happens in case of fork? Eventually, one can get lost because the guideline has broken. In such a situation, the systematic search for an object that doesn’t exist will fail.
I think that what matters is, again, the knowledge of surroundings, including not only the mineral parts of the cave but also the guideline and other artificial objects as well as the diver. Anticipation is very important. In each part of the cave, the following questions must be asked permanently:
Very often, the most obvious or direct solutions are different from the pedantic methods that are regarded as universal. If no solution arises, this means that the incursion turns to be very hazardous and should be postponed or that one has to give up.
20 March 2005
We have worked hard in our barn. After that, I went to dive the Combe du Creux again. It has been a readjustment dive with just two 12l tanks. When starting, I felt not at ease, but it has improved once inside the cave. The dive lasted slightly more than one hour. I think my consumption was too important (2,400 litres), though I finned only 200 metres in the deepest zone. Anyway, a mean consumption of about 14 litres per minute has no meaning, though what happens during decompression stops and when finning in a deep gallery is different.
In the deep zone, my mind was not quiet, and I felt narcosis. Especially, my sight was shrunk, and any decision was slowed. This is what has limited the dive. Giving up is the only means to be able to try again. This is very similar to what happens with martial arts. The difference between being the winner and being the loser depends upon very few things, and what matters is to be still alive. I have no propensity for sheer risk, but cave diving is the only moment during my life where I can do what I think of and where I can think of what I am doing. From the point of view of Buddhism, this is a fashion to practically understand some principles, for instance that I is nothing. This is also a fashion to approach impermanence. I do not regard myself as practising Buddhism. I don’t belong to a Buddhist community, and I have no master. I just read books, which is perhaps less disappointing. Anyway, if I were Buddhist, it would be an impure Buddhism, which looks like the one of medieval Japan. It would correspond to a very impure mix of philosophy and concentration on one hand, hardness and violence on the other hand.
9 July 2005
I have dived in other caves, the Source de l’Écoutôt and the Gouffre du Paradis. Some rest would be needed. I am slow and less resistant to cold. The sky is overcast, the weather is not very beautiful, and sometimes it rains. This is demoralising. I have taken several cross sections in order to produce a valuable survey. I had planned to visit the ascending part of the pit, which leads to the deep zone. I wanted to reach its free surface of this pit, but I was too chilled. The sump was quite clear. I went back and observed the secondary passage at -6 metres where I had laid guideline several months ago. It stops below an impenetrable ascending shaft. If it communicates with the pond, I did not saw any daylight.
I have let two oxygen tanks and a reel in order to do an incursion next week, if the weather is beautiful, if I am in the right mood. I spent a lot of time between -26 metres and -14 metres because of the cross sections. I consumed 14 litres per minute, which is encouraging.
10 July 2005
Back home in our flat. I can shave myself, have a shower, eat correctly and sleep in a bed with Nathalie. This is the rest I needed. I have received very disturbing emails, and I must be very careful regarding my answers. Any weakness will allow some rival cave divers to give me new problems. Any appearance of weakness, as well as any appearance of force or power, can be a prompting to ordeal and can trigger catastrophes. Alone, I was quiet and not disturbed by all those problems. I think that one of my close friends has probably gossiped about what I did the last week. This explains perhaps this explosive situation.
Nine years later, I do not remember the subject of those emails. A certain group of cavers spend a lot of time to discuss about what other cavers do and think. They should do more caving by themselves. Despite all the efforts I have made, I still belong neither to the category of basic cavers who must believe in some haughty idol nor to the category of haughty idols who are obliged to cultivate their superiority. What matters is to do caving and cave diving at the highest possible level. I think of a level corresponding to material difficulties, not a social one.
18 July 2005
The water level is low. I was obliged to crawl and to carry my tanks through the entrance that was not flooded. I dove in the branch, which is at right. I used two 18l tanks, one 12l stage tank filled with 43% oxygen gas mix. I have laid 15-metre guideline beyond my terminus of the past year. I felt narcosis, but I am very happy not having being disturbed by thoughts about the recent emails. I mainly worried for Nathalie who was waiting outside. I had planned a dive of two hours’ runtime. I remember having asked myself if I had to go farther. The visibility was bad, and a little silent voice has said ‘murderer’ because scaring the girl who waits isn’t a good thing. Even if I am in a critical situation, with many doubts and questions, I was from a technical point of view very at ease in the cave. The gloves I wore were a very good protection against cold, and I had supplementary underclothes, which afforded also a good thermal protection. In addition to the lamps on my helmet, I had a 5w lamp on my left wrist, which was very efficient. Its position avoids suffering light diffusion. In the deep zone, I took only one cross section, near the flag 290 metres, and I consumed less than 15 litres per minute. The intermediate zone is always the most difficult. I consumed 17 litres per minute and only 8 litres per minute during the oxygen decompression stop. One of the oxygen regulators failed because its gasket was extruded. After the end of the dive, I let the tanks in the cave, obliged myself to avoid any effort during one hour and drank several litres water. This time, the decompression has been very good without phosphenes, without skin problems.
29 July 2005
After having mowed the grass near our barn and written some articles, I was back to the Combe du Creux. In the passage, which is at the left, I tied a new guideline at the point where the flags stopped, near the flag 500 metres. I took two cross sections at the points 300, metres and 345 metres. Here, one can find on the right bank a kind of small meander and also some potholes. It is sure that in a past epoch, this part of the cave was not flooded.
Before trespassing the deep zone, I have put a part of my ballast in order to be lighter and more at ease. When finning back, I have found the water quite dim with small flakes. Narcosis and cold ran in a cyclic and coordinated fashion. Sometimes I felt in a good mood, and sometimes I felt in a bad mood. In order to move back faster towards the exit, I have used all the holds I could find in order to pull myself. This very special kind of climbing saves up time, efforts, air and decompression time. During a short moment, because of narcosis, I did not remember very well where I was, but with the systematic arborescence of the guideline and its flags, I encountered any problem… . The different caving projects I manage feed each other, and if we succeed to go back to Morocco, I will probably remember there the Combe du Creux. Vertical caving and cave diving are the two only things that interest me. Taking some time and dives in order to study the cave is more interesting than laying guideline in a hurry. This is a fulfilment, not a drug.
19 December 2005 (Pictures 7.5 to 7.8)
I arrived at the barn very late in the night. I was very weary because of problems in my family and because of the kind of moral decay I can see in the milieu of caving as well as at job. ‘Positive discrimination’ is still a kind of discrimination. I am angry, which sustains weariness. Regarding caving, I must be very careful and avoid vital mistakes. When deeply developed, the opinions of some of my friends or former friends become cumbersome logical paradoxes. For instance, one of my friends does not like people who belong to a certain federal instance because of their low level of knowledge. But my friend has friends who have exactly this same level of knowledge. That’s just hell!
It was raining, and the water level was high. It had a blue opaque colour even if nothing flowed in the fields. I installed a tyrolienne. It was a rehearsing of what will be necessary next summer, and even now, it has been helpful to transport my tanks without efforts. I have developed the right technique, and I am able to ascend and descend along the oblique rope. This is a pleasure. I have worked a lot in order to prepare the tanks. I had no longer oxygen and have been obliged to buy a new oxygen tank. The weather is windy and cold with low clouds. I had planned to install the tanks today and to perform two incursions Saturday and Sunday, but eventually, I decided to install the tyrolienne today (in order to install the decompression tanks tomorrow) and to make only one incursion Sunday. Anyway, I hadn’t enough oxygen for two incursions. I went back to the railway of Besançon in order to take Nathalie. Then we went to the lodge in the small village of Montrond le Château. During winter, our barn is too cold, and we cannot sleep there.
10 December 2005
I was still angry against some institutions and the moral decay they promote; therefore, I had to be very careful in the sump. I had to dive in order to install the decompression tanks and train myself to depth. I was late when starting, for the weather, still cold and windy, was not incentive. Once in the water, I felt better. I put two oxygen tanks at -6 metres and a stage tank at -40 metres after what I sauntered in the deep zone, up to the potholes. I have felt no narcosis. I have come back just when my diving computer started to indicate some first stops at -6 metres. When I arrived in the shallow zone, it indicated a first stop at -9 metres. You must always pay at exit! After the dive of 90 minutes, I felt better and no longer angry. Very probably, I’m changing with a pace and in directions (solo caving) that are not understandable by other people. With the sunshine, the cold has increased. We have come back to the lodge, where a bottle of chardonnay and a cheese dish made with hot Mont d’Or and hot potatoes were waiting for us. We have had a good evening despite the presence of another group of cavers. They were not very interested in solo caving, high-level practice, exploration and so forth. While I dived the Combe, Nathalie has worked in our barn. She has precise ideas about the place of the inner walls we will build and about other details. She is very motivated. Not being alone for such a project is essential.
6 July 2006
It was raining, and I was weary. Because my LED lamp has failed, I had another lamp to test. I found a rope in the entrance of the cave, with a fluocaptor tied on. I carried a camera, but because of the moisture, it did not work properly. I was unable to take good pictures. On the contrary, the new LED lamp worked perfectly. I am satisfied, the two 12l tanks I used comfortably allowed myself to fin in the deep zone. I went out with more than 150b in each tank.
14 July 2006
I installed stage tanks in order to perform an incursion. I escaped from familial events. I have had an intense feeling of loneliness; nobody understands what I am doing and how it is important to me. The only people who could partly understand are hostile rivals. Outside the cave, the weather is very hot, and associated with my thoughts, it creates a kind of shock. I have torn a piece of my dry suit. There was again moisture inside my camera, and in addition, I was not very concentrated. I have over-consumed and almost missed the -3-metre decompression stop … except if I find something new and extraordinary—this is my last incursion in this cave—it is time to stop the process. I feel free, for I am no longer interested in many things that prevented myself to progress.
17–18 July 2006 (Pictures 7.9 to 7.14)
In order to keep cool during dressing and departure, I went near the cave yesterday evening; and I installed a tyrolienne, carried the tanks near water. Its level was low, so I was obliged to crawl into the entrance which was not flooded. I even prepared the small material, fins, mask and other instruments. After that, I slept near the pond. Early in the morning of Tuesday, I woke up, ate breakfast and went on for the incursion. I let a message to Nathalie, who had planned to join me after the incursion. In case of decompression sickness, her help could be warmly welcome.
This kind of organisation allows to avoid any stress and to avoid efforts and sweat before diving. The tyrolienne avoids many efforts after the dive. All the preparation was fine. I have been able to repair the part of my dry suit I had torn. I have been quick to install this tyrolienne. I made some technical notes about that:
The night has been short but nice. Living during a moment near the pond, sleeping on the pebbles transported by water in a place where it has flowed and will flow again is very fairy tale-like. In addition, this magical place is in the woods. At night, one can hear animals and noises due to the wind and the trees. And I can entirely belong to what I am interested in.
The evening has been warm, but the morning has been quiet and cold. The grass is full of dew. I have been very happy to roll myself in a blanket during the breakfast. After, time has begun to flow at a higher speed. There is no time to think of beloved people or of future endeavours. One lacks time even to think of the fact that the present action is engaged. The fact that the probability of dying isn’t null.
I dressed polar underclothes, with a pair of leggings and a polar shirt below. Then I dressed the dry suit. Alone, it needs a tree, a rubber band and a carabiner in order to close the zip. Finally, I equipped myself with instruments, tanks and so forth and entered water. I scarcely have dived early in the morning, but this is quieter. It resembles to the only occupation that should be mine in a perfect world. I started carrying a 60% oxygen stage tank and a 24% oxygen tank devoted to progression in the deep zone. The first stage tank has been jettisoned after 8 minutes, and the deep zone has been reached after 13 minutes. Some ballast has also been jettisoned. Ballast can be heavy and cumbersome at the beginning of the dive but be very useful at the end when one needs to balance the buoyancy due to empty tanks and the need of air in the suit against cold.
What follows was like a dream. Perhaps was it really a dream?
Progression: all was quiet on that front except for a slight narcosis at -46 metres. The last stage tank has been jettisoned too. The morphology of the passage was useful as a stimulation against monotony. Progression again: all was still. First fork: at left. Second fork and finally the terminus of the previous explorers has been reached. Then it has been time to lay some guideline. The passage’s shape, the possible rubbing, the possible traps had to be anticipated. Caving reflexes have arisen as in vertical caving. The passage was quite narrow, with clay dunes. I have been obliged to stop on such a dune, and I abandoned the reel. Either I would come back in an indefinite future or it would be the task of someone else to see it and, why not, continue.
It was time to come back towards the exit. Curiously, I remembered absolutely any number, but I remembered perfectly having read my timer, my depth gauge, my pressure gauges and my compass, comparing the indications with the thresholds or what was expected for safety purposes. Of course, I made a survey. Towards the exit, the depth increased slightly. So I felt again narcosis below the -40 metres. When I recovered of the first stage tank, it had been impossible to open it, so I continued using my back-mounted tanks. I recovered my second stage tank and my ballast and made the first stops with a 60% oxygen mix. These stops were ‘long’, but the oxygen decompression stop had been longer: 50 minutes. After a short stop at -3 metres (one is never too careful), I was able to go out.
I planned the decompression using Visual Deco, a Java program I have built and which was based on more refined things than the currently available Haldane’s, Bühlmann’s and Workman’s theories. I have very well felt that the decompression quality has improved, and I have no longer had the minor pains encountered in the past. I have told other people that I was doing researches, but they seemed not very interested. The fact they want to use my results or they would be able to understand them no longer matters.
I went out of the pond, leaving all the tanks in the water, tied on a rope. This had been too cumbersome in the passage where one must crawl. Then the first things have been to find something to drink! I had prepared two pills of aspirin in case of problem, but nothing arose.
Meanwhile, Nathalie had arrived, and she had taken pictures. I climbed along the ladder and removed my suit and small gears. After that, we lunched under the sun shafts. I warmed slowly, whereas she found the place too hot. After the lunch, we hauled the tanks. It needed time and effort, but they were less intense and irregular than if I had been totally alone for that part of the incursion.
This was my last dive devoted to exploration in this cave. I have made here other dives with other aims: sometimes to test a model of rebreather, sometimes to keep a close eye on what rivals are doing, sometimes just because I wanted to visit an old friend and discuss a little a bit with her. I have not dived the terminal sump of cave of Combe Ainée (Picture 7.15), which is a presumed upstream. Alone, it would be too difficult and a human junction between both caves seems to me very unlikely.
15 October 2006
With Nathalie and his brother, I went back to the Combe du Creux in order to test a model of rebreather. This cave has been chosen because it is not a straight tube and because a rebreather devoted to decompression must be tested in a cave where decompression may really occur. It was raining, so we let the material in the meadows and went back to the road with the car in order to avoid any surprise. Using this new material is not painful, not difficult as it was before I made some improvements. Carrying the material is easier than the exploration of the last summer. Once in the water, I began the trial without fins, and I found myself perfectly able to slip on them. I dove during 21 minutes without problem. It had become realistic to use such a material for explorations.