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| Elaine descends the pitch in the Event de Perdreau |
The existing survey of the Perdreau (Siphon Nord – North Sump) gets a bit flaky at sump 2. It is merely reported to be 100m long with a maximum depth of -18m. Oz and Joe were to go in and survey the sump properly with station depth, direction and distance and to survey as much of the new line as they could. They dived a pair of 7l ‘safety’ bottles through sump 1 to allow divers to start sump 2 on fresh cylinders and also to add a bit of safety for the return journey back through sump 1 incase a diver had a problem or a cylinder go down which was unfixable. The water is cold and we were in wetsuits, so hanging about in the cold water because of a problem wasn’t really an option here.
Joe and Oz came back with survey data confirming what we had hoped for. The length of sump 2 was indeed 100m and the new line was in addition to that. They managed to survey the first 10m of their new line before gas and cold turned them back.
Meanwhile, Rich and I sat huddled up at sump base, kitted up in wetsuits and wrapped up in suit bags and oversuits to keep warm while we waited over an hour for them to return. After a moment of worry and ‘what happens next’ planning, Rich and I were about to leave the dive base to go and get warm on the surface and hatch an action plan when their lights could be seen returning back to dive base. They were so cold they could barely speak – but they had done an awesome job of painstakingly surveying the sump until the new line and a third of that too.
Joe writes: “We dived through Sump 1 with the aim of re-surveying the existing line in order to provide data on the position of the start of the new line laid in the previous dive. Although the existing line was tagged, this was very loose in places and so each section between belays was measured with a measuring stick along with depth and azimuth information. The full data will be added to the survey held by Nathan Boinet, however the junction with the new line was measured at 83m from the start of Sump 2 putting the total distance (including the new line) at around 121m. Gas reserves prevented the full survey of all of the new line, however its overall length (from knots and tags) as well as trending direction was noted from the previous dive. A possible further new passage was briefly investigated on the return through Sump 2 which, from the general direction and type of passage (matching the one in which the divers had laid new line) was thought might bypass the rift to connect with the new passage.”
Then it was mine and Rich’s turn to dive and hopefully extend the line in the new passage. We both had a whiff of trimix in slightly bigger cylinders to aid with the depth and clear thinking in cold water.
We warmed up and kitted up, before setting off through sump 1 without issues. We climbed out of the water and got fairly quickly into sump 2. As we set off, it was obvious that the visibility hadn't settled since our last dives here and Oz and Joe surveying had inadvertently stirred it some more. The rift half way through the sump is narrow and it's impossible to dive through it, never mind survey it, without touching the walls which expel a powder-like dust which hangs in the water and doesn't move on as there is no flow here.
I dived through what I thought was the rift and met the junction with the airbell. I turned downslope and was now in completely zero visibility. I felt uncomfortable as the line was very, very loose in my hand and there seemed to be miles of it and no belays. I'm used to diving in zero visibility and it never worries me - unless the line is so poor that following it blind becomes dangerous.
At that moment, my hand followed the line into a pile of boulders and seemed to be snaking in amongst them. I couldn't feel any space around me or ahead of me and I knew the line had gone into a line trap, pinched between boulders, possibly metres from the actual way through.
I'm not playing this game! I've been here before, upside down in a boulder choke in zero viz, following slack line, with the clock ticking, only that time I was in Wookey 25 and I was trying to get home....
Not today.
I figured if I couldn't find my way into the cave, there was even less chance of finding my way out. I couldn't see what the line had done to even attempt fixing it. I backed upslope and tried to turn around. I could hear Rich bearing down on me and I felt around for his thumb and pulled it. He got hold of my thumb and pulled it back, indicating that he understood my signal to go home.
We learned a lot from this dive. With little or no flow, the cave does not clear while divers are in there so our only hope from now on is to fix that line and make it followable in the worst visibility, which is the first job for our next attempt at the project in 2012.
Disappointed, but certain that I had made the right decision, we left the cave and just managed to get all the gear out before dusk.
But not without drama!
Oz got half way through the boulder choke and I was close behind when I heard the most blood-curdling scream! Oz was wailing like a girl and I thought he'd either been squashed by a rock or had met a 'vipére' or something.
No, there was a "f***ing tarrantula" in the boulder choke and Oz was face to face with it!
I tried to belittle it with sentiments of "It's only a cave spider" and "It can't be that big"...
Anyway, I got into the choke myself and OMG!!! It was not only huge, but extremely ugly. It's eyes were shining and everything!
We scared it away - which took some doing - this thing wasn't scared of anybody..It didn't scurry or scuttle like normal spiders..this thing crawled. It was disgusting!!
We managed to get back for tea and medals and Rich and I declared that we wanted another day off tomorrow to sit on the beach, swim and sunbathe and do the square root of bugger all!
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| Joe gets his gear together |
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| Joe and Oz set off into sump 1 |
Meanwhile, Rich and I sat huddled up at sump base, kitted up in wetsuits and wrapped up in suit bags and oversuits to keep warm while we waited over an hour for them to return. After a moment of worry and ‘what happens next’ planning, Rich and I were about to leave the dive base to go and get warm on the surface and hatch an action plan when their lights could be seen returning back to dive base. They were so cold they could barely speak – but they had done an awesome job of painstakingly surveying the sump until the new line and a third of that too.
Joe writes: “We dived through Sump 1 with the aim of re-surveying the existing line in order to provide data on the position of the start of the new line laid in the previous dive. Although the existing line was tagged, this was very loose in places and so each section between belays was measured with a measuring stick along with depth and azimuth information. The full data will be added to the survey held by Nathan Boinet, however the junction with the new line was measured at 83m from the start of Sump 2 putting the total distance (including the new line) at around 121m. Gas reserves prevented the full survey of all of the new line, however its overall length (from knots and tags) as well as trending direction was noted from the previous dive. A possible further new passage was briefly investigated on the return through Sump 2 which, from the general direction and type of passage (matching the one in which the divers had laid new line) was thought might bypass the rift to connect with the new passage.”
Then it was mine and Rich’s turn to dive and hopefully extend the line in the new passage. We both had a whiff of trimix in slightly bigger cylinders to aid with the depth and clear thinking in cold water.
We warmed up and kitted up, before setting off through sump 1 without issues. We climbed out of the water and got fairly quickly into sump 2. As we set off, it was obvious that the visibility hadn't settled since our last dives here and Oz and Joe surveying had inadvertently stirred it some more. The rift half way through the sump is narrow and it's impossible to dive through it, never mind survey it, without touching the walls which expel a powder-like dust which hangs in the water and doesn't move on as there is no flow here.
I dived through what I thought was the rift and met the junction with the airbell. I turned downslope and was now in completely zero visibility. I felt uncomfortable as the line was very, very loose in my hand and there seemed to be miles of it and no belays. I'm used to diving in zero visibility and it never worries me - unless the line is so poor that following it blind becomes dangerous.
At that moment, my hand followed the line into a pile of boulders and seemed to be snaking in amongst them. I couldn't feel any space around me or ahead of me and I knew the line had gone into a line trap, pinched between boulders, possibly metres from the actual way through.
I'm not playing this game! I've been here before, upside down in a boulder choke in zero viz, following slack line, with the clock ticking, only that time I was in Wookey 25 and I was trying to get home....
Not today.
I figured if I couldn't find my way into the cave, there was even less chance of finding my way out. I couldn't see what the line had done to even attempt fixing it. I backed upslope and tried to turn around. I could hear Rich bearing down on me and I felt around for his thumb and pulled it. He got hold of my thumb and pulled it back, indicating that he understood my signal to go home.
We learned a lot from this dive. With little or no flow, the cave does not clear while divers are in there so our only hope from now on is to fix that line and make it followable in the worst visibility, which is the first job for our next attempt at the project in 2012.
Disappointed, but certain that I had made the right decision, we left the cave and just managed to get all the gear out before dusk.
But not without drama!
Oz got half way through the boulder choke and I was close behind when I heard the most blood-curdling scream! Oz was wailing like a girl and I thought he'd either been squashed by a rock or had met a 'vipére' or something.
No, there was a "f***ing tarrantula" in the boulder choke and Oz was face to face with it!
I tried to belittle it with sentiments of "It's only a cave spider" and "It can't be that big"...
Anyway, I got into the choke myself and OMG!!! It was not only huge, but extremely ugly. It's eyes were shining and everything!
We scared it away - which took some doing - this thing wasn't scared of anybody..It didn't scurry or scuttle like normal spiders..this thing crawled. It was disgusting!!
We managed to get back for tea and medals and Rich and I declared that we wanted another day off tomorrow to sit on the beach, swim and sunbathe and do the square root of bugger all!
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