> The Dive

Setting off

Michael Waldbrenner's first person account of the dive...:

This night we went to bed at around 9 pm. We met again at 05:30 and had spaghetti for breakfast. We then dressed up and the heating system for the deco was checked again as we stood in the water. 2 guys in dry suits helped us into the rebreathers. We connected a 50/25 stage for traveling to the shaft and clipped and connected an additional 14 cu ft stage with argon. We fired up the 18W HID 20 Ah Ni-Cad lights and took off at 06:41 am using a long tube gavin scooter for the 8-minute-ride to the shaft.

We clipped of the long tubes scooters and swam down the shaft. At 21 m we clipped off the travel stage with 50/25 and picked up the 60 m trimix stage with 19/65. We checked each other with a short OK and left for the end of the shaft where we picked up 2 magnum scooters each and continued the journey.

The deep section

At 600 m we picked up the 4 other magnums and at 800 m we dropped the 60 m stage, the argon stage and picked up one fresh 60 m stage with 19/65 and a fresh 30 m stage with 30/50. I changed from rebreather B to A.

We were now each equipped with 4 scooters and 2 80 cu ft stages. The rebreathers had double 20 L tanks for bailout, containing the same gas as in the deep stage.

The primary lights should last around 10-11 hours. With the rebreathers, the dump ratio is 1:8 so we had as much gas as if we carried 16 stages! We also constantly switched scooters to assure they were working and to let them rest from time to time giving a longer burn time.

After 131 minutes the cave went shallower than 50 m. At 160 minutes the line was broken and it took quite a while to find the connection. To me it looked like a dead end, but Reinhard knew this place and found the connection. We placed around 160 m line here and continued.

A scooter is trapped

Well, I found the rest of the line when I scootered upwards and caught it in the prop. The line was hidden behind the shroud and I had no chance of seeing it. We tried for 20 minutes to free the scooter but could not manage it. We abandoned the scooter and clipped it to the line. We had talked about "what ifs" prior to the dive so it was clear that we would continue the dive (We have later done slight modifications to the prop compartment and are now able to to complety disassemble the unit under water and reassemble it again). In the unlikely event of a rebreather failure we would have turned for the exit.

When reaching 3200 m we left the first trimix stage behind and at 3500 m we left 3 scooters behind. After 221 minutes we reached the end of the line at 4300 m in 32 m's depth as Olivier had described it to us. The room was round at the far end with a small crack above the floor. The crack was only 0,8 m high but big enough to continue.

Laying new line

Reinhard connected the big exploration reel with more than 1000 m of 2,5 mm nylon line and I took all but one scooter from him. From now on we entered untouched cave tunnels. On the 2 reels I carried there were more than 1000 m of additional line (1,5 and 2,5 mm). All line was marked every 20m.

Directly after this crack the cave began to drop. Reinhards laid line while scootering and I was lighting his way and his tie-offs. After this we had to connect the back gas due to the depth. In the dive planning we agreed to call the dive if the cave got deeper than 60 m and when we hit that point at 258 minutes, we exchanged an OK and agreed to continue for 5 more minutes to check if the cave got shallower again. After laying 700 m of new line to 5000 m – and reaching af depth of 64,6 m – I called the dive and hit the marker button on my Suunto Vyper gauge. We left a small item as a gift for the next explorer and headed home. We turned after 262 minutes leaving the Doux de Coly the longest continuous underwater cave in Europe.

Going back

"Too bad that the cave dropped so deep", we thought during the ride home. We continued to change scooters but I stayed on rebreather A because I wanted to see how long the scrubber would last.

As we picked up the dropped 60 m stage I shortly switched to rebreather B to check it and back to A again. We also picked up all scooters and finally reached the first home base were we had dropped the argon stage and the other 60 m stage. The Vyper showed 375 minutes at that point.

Decompression

Now we were almost home. When we reached 45 m we clipped all scooters and all unneeded stages off and continued our deep stops (at 80% of the total ambient pressure of our max depth) until the first "real" stop for 8 minutes at 42 m. Here we changed to the 40 cu ft of 30/40, picked up the heating batteries and connected them to the heating-shirt. I fumbled around with the Gatorade that was deposited here and drank half of it.

After our take-off, a support crew every hour scootered to the shaft to check for our arrival and therefore it took only a few minutes until we saw the lights of the "Welcome" team dropping down the shaft.

We wrote "5 km" and "everything OK" in the wetnotes to give a status report to the whole gang. After the 42 m stop we clipped the heating tube to the mountaineering clamp and pushed it upwards. The argon tank fixed to my doubles was empty at this stage so I switched to 14 cu ft tank we also used for riding into the shaft.

Reinhard was hovering around half a meter next to me. Due to the fact that the shaft is vertical, we had to hover for almost the entire deco so I almost completely emptied my wing and put more argon into the drysuit. I put my head down and felt the gas floating into my drysuit feet. We both did some stretching and as my back ached I tried to curl myself together like an embryo.

Here at 39 m I smiled, thinking that our stop depth is a deco dive for sport divers.

Food and drink

The next team arrived and asked if we needed anything. I wrote something in their wetnotes which I cannot tell to the public but also wrote "a Big Mac menu", as a joke, because I was getting hungry.

We then got the first hot drinks, or better I should call them lukewarm. We used a food tube for the transport which actually looks like a acrylic light canister (which it in fact was in its former life).

Doing the deco

Getting up to the 36 m stop, we switched to trimix 35/35 as deco gas and left the 30/40 behind. Before switching to the 50/25 at the 21 m point we did a 15 minute break with the 17/55 on open circuit. The reason for this is to prevent further swelling of the lung tissue on high PO2 which could happen when we switched to the 50/25. You really feel how good the 17/55 is for your lungs and this tank was also used in the habitat for breaks. During those breaks the slower tissues feed the faster tissues with inert gases and when then switching back to the deco gas, the fast ones almost unload immediately, so these breakes are given full credit as deco time.

Switching to the break gas also gave us the chance to have different mouthpieces and this is really convienient after the 557 minutes that I saw on my timer at that point.

I switched back to rebreather A which I used almost the whole time. Only on the way in had I used rebreather B and only check to see if B was working as it should. I wanted to see when the scrubber broke. I used rebreather A for 11 hours in total and B for around 1 hour. Reinhard changed them regularly and had 13 hours on the rebreathers in total.

During our deco on 50/25 we did breaks every 15 minutes for 5 minutes on 17/55. We still had to hover in the shaft and I started just to signal the incoming crews with an OK sign behind my back because I got too lazy to turn around every time.

After 10,5 hours Reinhard's Ni-Cad Light canister was empty, but my new batteries still had 1 hour more burn time. This was really exactly the burntime we like to have for explorations and for solving problems. In case we would have needed more time, or a light head had failed we had a 10W HID head in my pocket and Reinhard had a 30W halogen head with him. We were carrying 3 Barry Miller Scout lights and one LED light each.

Reinhard looked over to me and we exchanged an OK sign. It is important also to check your buddy regularly during deco. Most people tend to think the diver is over (well, me too) but you still have to be aware of things like oxygen toxicity.

The habitats

The stops got longer and longer and we are waiting to enter the habitat soon. The 12 m stop was scheduled for around 70 minutes and we were now at the depth of the spits of my habitat. After 730 minutes, Reinhard swam over to his habitat and let the support divers help him out of the rebreather. I smiled, because he had already prepared everything for them, and I heard him muttering while getting out of the kit. He watched the divers while they swam the double RB80 up the shaft. He had had 16 kg of lead clipped onto a weight belt with 2 D rings that he had just put on. He was on his 17/55 for another minute in order to finish the 15 minute break before getting to a high PO2 again in the habitat. He swam into the habitat and pulled the seat upwards and vented the habitat with air.

The supporters swam over to me and helped me getting the weight belt on, clipped on the lead and helped me getting out of the rig. I am sure it did not look as cool and easy as it did with Reinhard, but we managed it. I entered the habitat, blew out the water and was sorry that I had to leave the heating tube behind.

When fully inflated the habitat has a postive bouyancy of around 800 kg, and they were each held by 6 spits on two ropes. A spit is a drill and a dowel in one piece. It is spreading itself inside the hole and gives very secure fixation point.

More food and drink

I was really looking forward to the first real hot meal and opened the transport tube and it smelled like noodles. After taking my portion out, I closed the tube and it was brought over to Reinhard.

We kept fins on, our weights attached, and had the trimix stage inside the habitat for security reasons. Due to the high PO2 of 1,9, we did breaks every 12 minutes for 8 minutes. We had planned around 3 hours on O2 and out of my window I saw Reinhards feet dangling, so he was OK.

Later the food tube was again brought to me and I could hardly believe it: a complete BigMac menu! The closest McDonalds is in Brive, which is at least a 30-minute-drive from Coly. The ketchup was missing and the Sprite was tasting horrible but I really laughed out loud. This was a cool joke, eating a BigMac 300 m in the cave, sitting in an underwater tent, breathing oxygen after a long dive.

Well, one crew after the other showed up but it was a bit boring, because they forgot my book. We wrote in the wetnotes that we wanted to leave at 22:45 so around 22:30 the "exit team" showed up.

Exiting the cave

We did another 15 minute break because we did not want to go back into the water with high blood levels of oxygen whereafter Reinhard exited his habitat first.

I could see Tom holding out a backplate, a canister light and an argontank for Reinhard, but he just passed Tom and swam upwards the to the top of shaft with a stage in his hand. Tom and Peter quickly followed him. As it turned out Reinhard had planned to do this all the time but Tom and Peter had been told this by the other support divers! The surprised divers watched him as he got back into the rebreather.

I decided to pick mine up over the next days and so I glided out of the habitat where the support divers helped me into the backplate and we went up the top of shaft were we met with Reinhard.

We clipped on the scooters and hit the trigger. After 8 minutes we arrived at the cave entrance where chemical lightsticks had been placed on the last 5 m of the cave line. This was nice!

In the pool we stretched and checked for signs of DCS and relaxed a bit in 6 m's depth. I wanted to see the Suunto Vyper rolling over from 999 Minutes to 000, but it just stopped at 999. "Ok, so what", I thought and we ascended at around 1 m/min.

Champagne!

Directly after breaking the surface we were welcomed with champagne that was poured over our heads (we even drank a bit of it, too). This was really a warm welcome the French way! Everyone was standing there and was happy.

Reinhard and myself looked at each other and we were really smiling. What a cool dive! The surface gang had placed candles everywhere and the scenery was beautiful.

We stood in the source pool for around 10 minutes to check ourselves for symptoms of DCS. Due to the fact that Reinhard left his portable chamber at home and the next chamber was in Toulouse, hours away, we were prepared for in-water-recompression. As we had no chamber near us and no possibility of a swift helicopter flight to a chamber also was the reason why we decided to deco 1,5 hours longer than absolutely necessary.

The barbecue was ready and so we exited the water. As we weren't tired we joined the others for a late dinner and talked for a while. After being out of the water for around 30 minutes we checked ourselves for bubbles using a Huntleigh doppler. We had no bubbles at all, so back to the dinner...

The next days we hung lose, shot some video and did some fun dives. The visibilty improved from day to day in the Doux de Coly. Due to the fact that we had to turn around at 5000 m, as the cave went deeper than our gas mix allowed we can safely say that this is definitely not our last dive in the Doux de Coly.

Equipment information

Decoplanning was done using DecoWeenie with a GF Lo of 0,1 and GF Hi of 1,2 and then shaped manually.

The most impressive thing on this trip was the fun and the team spirit! We were divers from 7 countries, some meeting each other for the first time and we really had a good time and got the job done. We owe this success mainly to the DIR system!

Dives at this level require some special equipment, with a part of it developed and/or produced by ourselves. This includes the heating system, the food tube, the magnum Gavin scooters, the P-valves, the 20 Ah Ni-cad canisters, the rebreathers, etc. The magnum scooters were based on the Gavin scooters George Irvine is selling and the rebreather is now produced and sold by Halcyon.