Photos (c) Brigitte & Thierry Baritaud, Rose Yates, Jerome Meynié
D4 The Big Worry
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Descent without worries:
It proved difficult to wake up at 7am, mainly due to the foggy freezing climate of 1 degree celcius outside ... we really needed all of our motivation .
At the dive site, Thierry (in-between his koala-style tree napping) worked out a perfect system to download into the pond the 40 kg Silent Submersion UV26 scooter, twin 20 litre stage tanks for deep safety, and finally the ventral backup rebreather for the decompression line..
A good mood prevailed whilst kitting-up took place. We then chose a very careful path down the muddy slope, trying our best to avoid any remaining broken glass, as any cut on the drysuit becoming a night mare for the 7-8 hours underwater expected.
Once in the water, I took my time to warm up the scrubber and check that I hadn't forgotten anything of importance !
I made my way down to –6m on pure oxygen whilst checking the three oxygen sensors from IT Dr Gambert are all showing a PpO2 of 1.6. Then I switched-on my travel off board gas, a 15 litres at 250b of 22/78 (22% O2, 78% Helium), for that I had to flush three times the loop by inhaling by my mouth and exhaling by my nose, thus getting rid of the pure oxygen before my descent and avoiding a rise of PpO2 of 2 or 3 bars.
At -21m I installed the backup ventral rebreather on the ascent vertical rope primarily as a back-up, but also to do my long -6m oxygen decompression stop on my way back up.
Then I dropped down to – 40m in the Big Black pyramid cave without any landmarks except the descent line, perfect conditions to focus my attention on the functional noises of the rebreather: automatic diluent valve opening and O2 solenoid firing to keep my PpO2 at 1.0 bar. At the bottom of the descent line I had to follow the deep path shown by a snoopyloop ; )
Following a silty slope, I passed the "straight rock" and then arrived on the side of the North Cliff.
The visibility wasn't fantastic, a maximum of 3-4 m. I dropped to –62m where I attached my 15 lit 22/78 stage tank on the blue old English line, and then I switched via the whitey valve to the on-board 3 litres 7/93 (7% O2, 93% He) followed one more time by three flushes to clear the loop. Unfortunately, exhaling by my nose some gas bubbles began to tickle the silt above me : ///
I also tested the two open circuit regulators of my safety stage tanks, big mistake, by doing so all of the bubbles I exhaled detached a big cloud of silt from the wall of the cliff and the ceiling of the gigantic room. I promptly switched back to the rebreather and moved away.
Starting my descent, I turned my back to the
cliff and moved further South in the blackness of the (big, gigantic ?) room
with all my senses in alert.
Around -110m I slightly slowed my descent speed as I could see silt moving
laterally. No, I wasn't narked as I was using heliox! Could it be possible that lateral
gallery existed in the large mysterious unobservable surrounding area?
The second lethal mistake made, was not looking where I put my fins. After trapping the line in a dead tree branch at -120m, I moved away using the Silent Submersion scooter, and whilst I pulled gently on the line all the silt started to follow : //
Around –130m the visibility became slightly better (3 m), I observed a 45 deg slope (probably the one I crashed into last year) and a skeleton of a French Solex (moped). Yes folks, this is not a cave but a an underwater dumping pit …
Once more, at -150m there was a lateral current ??? It probably originated from an underground river coming from the village of Cubjac (4km away) and exiting at 250m from here in the big river « Isle »
Interestingly, I encountered 3 thermoclines: 8 degrees celcius at -150m (and later confirmed the coldest of the dive), 10 deg. at –50m and 12 deg. on the surface. Amazingly, this is the first cave in France where I've observed such a phenomenon. Throughout the Goul du Pont expedition the water remained at 13 deg. celcius on the surface and at –178m …
At -170m I slowed down my descent massively because the visibility reduced to only 50 cm. In a strange yellow fog, and without any landmarks to orientate myself, I moved very slowly away using the Silent Submersion scooter to avoid any further physical exertion and also in the hope of a finding clearer area.
But without success, with nearly no visibility I looked at the VR3 showing –184m 32 minutes bottom time, I pulled 170m of line from the -60m English blue rope, I was at 240m from the surface, it was time to go home ! 80 bars left on the on-board 3 litres diluent, 180 b on the oxygen.
Or « Souci » in the local county mean « Lost »:
As I ascended in zero visibility, my exhaled bubbles from the over pressure valve of the counterlung detached all the silt from the ceiling of the gigantic cave
At my first deep stop of –130m whilst, once more, fleeing a silt cloud, I succeed to tangle the line in the propeller of the scooter and around one of my lateral stage tanks. Keeping one hand on the upstream line, I cut the tangle downstream line.
As the cliff reappeared at around -100m, a massive avalanche of silt and rocks began. I just had time to pull myself against the cliff and shield my head under a rock "terrace", whilst there all I could do was listen to the repetitive disheartening noise of stones falling onto the back of my rebreather
After the 2 longest minutes of my life, the
rocks ceased to fall and I was wondering what the hell had happened. Had the ceiling of the gigantic cave collapsed? I thank God
I had, and always wear,
a helmet !!!
Meanwhile, the visibility had turned to zero - to read the VR3 it had to be put right in front of my nose. With my two 50 watt 'fog lights' off I tried to navigate with just the LED lights. Unsuccessfully I searched for the line I'd lost during the avalanche. A cold shiver ran down my back, was it the hypothermia induced by the heliox or just pure fear ...?
I had to stay calm and not panic.
Objectively, I had
more than 4 hours of gas with the rebreather and I could cover a great search distance with the Silent Submersion
scooter along the North cliff.
After 15 minutes scootering (speed 3 adjusted underwater) in bad
visibility on the East and then West direction, I found, with a big RELIEF, the
English blue line : ))) at around -65m.
At –63m
I took back my safety stage tank of 22/78,
and like a blind man I plugged it back on the rebreather Swagelock connectors.
Indeed, the procedure movements I had repeated over and over again
during the last few weeks became
very useful indeed.
At –40m I was back on the bottom of the pyramid shallow shape of the cave, continuing with my long decompression, and still maintaining manually my PpO2 at 1.3 bars. Then I switched to a 35/65 (35% O2 65%He)
At -21m I switched to 50/50 (50% O2 50% He), with a prior PpO2 drop of 0.2 at –24m for 10 minutes, to rest my lungs from that high PpO2.
At –18m I had some spare time so to entertain, I decided to do some topography of the ceiling. I attached my little 50m exploring reel to the decompression vertical rope and made my way along some cliffs, dead ends, and narrowness ...
But after 30m of exploration, my reel felt very smooth, no more tension of the line ... again that cold shiver on my back, my line was broken - I felt very very upset. Maybe I should have stayed on the deco-line and saved the topography for another day ... with a visibility 1-2m, it was difficult to follow the cliff back due to the many dead ends and the continuous variations in the wall shape. I couldn't stop thinking about Denis Sirven in the1998 Vaucluse expedition who lost himself on the ceiling of the cave ... once more, the long autonomy of the rebreather helped me to stay calm.
After another very very (very) long 20 minutes of searching, I found the vertical decompression-line rope. This time, I wasn't going to part from it, for love nor money, until after my exit on surface !!!
With one hand firmly on the line, I continued observing the geological variations within the walls and ceiling :
At -9m
I'd been on the rebreather between 1.0
and 1.3 bars of PpO2 for 4 hours with no signs
of hypercapnia and the « Spherasorb »
sodalime from
Intersurgical was still
scrubbing well.
Before going to -6m, I dropped the PpO2 to 0.2 bars, once again, to rest my lungs.
At -6m, I switched to my second rebreather: an O2 CCR Castoro C96 Pro that the Italian army kindly provided to me via OMG. Subsequently 3 hours were spent on oxygen with air breaks every 20 minutes.
At T + 4 hours Thierry came to greet me:
When he arrived my first question on my
slate was: "Did the surrounding field collapse or did
the pond became wider ? " Thierry
answered me very calmly "No, it's just a very
unstable geological area " …
He came back 1/4h later with my heating battery tube and
some hot chocolate : - )))
Thierry tough man in a wet suit without gloves, came every hour to see how things were going, each time creating a little avalanche of small stones:
My 3 hours at
-6 m were divided between my Game Boy,
"Star Wars Attack of the Clones",
and the book of David Poyer: "Down to a sunless sea". Upon
reflection, this book was a very bad idea to read
during decompression, as it was the story of a cave diver getting lost ... next time
you can be assured that I'm going to take a
nice French sexy novel from San Antonio !!!
The little fish and Perche came to say Hi:
I exited very slowly still on oxygen
With the best inentions, Tosca, my dog, insisted on a post drive oxygen-therapy session - I would have much preferred a kiss from Rose my girlfriend !
Epilogue :
" Le Gouffre du Grand Souci" (Cave
of the Big Worry) is really creating too many worries. Visibility is too poor
for proper exploration and topography. Since a few
months, we've been trying to build a sonar ultrasound scan (type Wakulla
2 1998
expedition) of two dimensions,
but we failed to make it work at such a depth..
The repeated falling rocks make the helmet an obligation, it would be foolish to do without, so DIR divers avoid the place.
The summation of the risks and the difficulties of investigation have halted
any ambitions of further exploration. Our time and energy will be better used in other caves with
less worries ; - )
My descent at a speed of below 30 m/min didn't create any High Pressure Nervous Syndrome on heliox. The possible issue of hypothermia was easily avoided by using proper protection: Xerotherm 4th Element underwear, and using an Otter Artic Plus.
Once more, the CCR Mk15.5 remains the weapon of choice! Working at a set point of 1.0 bar flawlessly, it gave me a good psychological confidence boost when I lost myself
The Silent Submersion UV26 scooter proved the perfect tool to move smoothly on my way down, avoiding cliff-bashing and reducing the risk of moving too much silt. The 19.4 bars of pressure didn't bother it at all, and even after the dive it didn't show any shape deformation. Again, when I lost myself, it helped me a hell of a lot to find my way out !
Many thanks to Major Rob Doncaster for his technical help on the Mk15.5 and for spending his time answering my never ending questions on military CCR dives. Next time I'll follow his advice and will put a micro grid on the back of the counterlung to try to reduce the size of the exhaust bubbles from the Over Pressure Valve. The militaries used it to try to stay unseen from the surface from the enemy, in cave diving I'll use it to avoid having my expanding bubbles detaching rocks and silt from the ceiling.
I'd like to finish by giving all my thanks to my friend Dr Cédric Eve for his long and huge work of synthesis on the Heliox tables from the Royal and US Navy but also from the professional commercial offshore industries on constant PpO2 dives on CCR of the last 20 years, that gave me the opportunity to exit from the water without fatigue or a DCI ! Many thanks also to the French local emergency team and to the hyperbaric centre of the hospital Pellegrin-Tripode from Bordeaux for being in stand-by just in case …
"It is not the mountain we conquer, but ourselves" Sir Edmund Hillary
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Copyright 2003 by Dr Jerome Meynie. All rights reserved. Revised: 12 Dec 2003 11:20:33 -0000.
