Prompted by the thread ?10 serious mistakes? I?d like to propose a new one ? what is the dumbest thing you?ve ever done underground? (Maybe Pegasus could organize a prize ? a booby prize, given the name of this thread!)
To start the ball rolling how about free-diving an unknown sump in a new cave?
Several years ago we were exploring a resurgence cave in Northern Spain, that comprised ~200 of fine stream passage, with one pitch of ~7?8 m to climb. At the end there was a sump. However, just before the sump there was a phreatic tube of ~1.4 m diameter emitting a howling draught, and we figured that this presaged a sump by-pass. So we set off in high hopes through passage that degenerated into crawling only to have them dashed when we reached a chamber where there was no obvious way on (although we could hear the tantalizing sounds of the stream coming up from cracks and fissures in the floor). Anyway, we had virtually given up hope of finding the continuing passage, and had gone back to a steeply-sloping bedding-plane crawl of ~0.4 m high down which we?d slithered; to our astonishment, there was a near-identical bedding plane going back underneath the one we?d slithered down, with the draught coming out of it ? it was as though we had a metre-high bedding split in half by a thin, albeit extensive, slab of rock.
Anyway, we followed the draught up this bedding, which eventually changed back to a nice phreatic tube, and continued until we reached a sudden drop into very deep water, with limited air space, through which was roaring a howling draught. We dropped into the water and swam along a canal and across a lake to the start of a fantastic vadose canyon leading off into the mountain, at which point we deemed it politic to abort (there being only two of us), making plans to return the following day.
The next day we went back, equipped with a diving mask, as I figured that the sump was probably quite short after all; and so it proved to be the case. You then had the choice of a piss-easy free dive of less than a metre or a grotty crawl of over 100 m, but even if you were severely aquaphobic, there was no advantage to going the long way because you were up to our nipples before you?d left daylight, and in any case you still had the canal and lake to swim.
So, after exploring several hundred metres of fabulous river cave, we reached a chamber (maybe 20 m in diameter, 10 high) with the water flowing out of a sump. I?ve never been particularly enthralled by the appearance of the typical British sump, but this was something again, crystal clear water flowing out of a passage some 3?4 metres wide and obviously fairly deep; so, I figured I?d free dive it . . . far away from home, with no backup; I recall that I was the only member of the party who had an electric light, the rest being on carbide. So I took a deep breath and dived into the sump. I could see (with the face mask) airspace ahead, and surfaced in it, only to find that it was merely an air bell. So there I was, treading water (did I mention that the water was very cold?) and wondering how I could possibly have been so stupid!!! So far, so bad, but it gets worse. I took a deep breath and tried to dive back out, only to find that I couldn?t overcome the combined buoyancy of wetsuit and lungs to dive deep enough to get back; the roof of the tunnel sloped down, and I had of course followed this downward trend, then it rose suddenly, more or less vertically, into the airbell, and I simply couldn?t overcome this downward drop. I have a memory (from some 40 years later) of starting to calculate how much air there is in an airbell about 2 m in diameter . . . ? a sphere of radius 1 metre is 2/3 pi r3 . . . which is . . . oh, f*** it, I gotta get out of here!!!
I contemplated several possibilities, including dying; one idea was to strip off my wetsuit while treading water, and dive out without its buoyancy, and then dive back (or send someone else back!) with a rope to drag out the suit (so why, given that we had a rope, hadn?t I used it for some sort of diving line?). I didn?t really fancy that, then I had another idea ? expel all the air (or as much as possible) from my lungs, and dive out with reduced buoyancy. This I did, and landed on the right side of the sump, gasping for breath.
To start the ball rolling how about free-diving an unknown sump in a new cave?
Several years ago we were exploring a resurgence cave in Northern Spain, that comprised ~200 of fine stream passage, with one pitch of ~7?8 m to climb. At the end there was a sump. However, just before the sump there was a phreatic tube of ~1.4 m diameter emitting a howling draught, and we figured that this presaged a sump by-pass. So we set off in high hopes through passage that degenerated into crawling only to have them dashed when we reached a chamber where there was no obvious way on (although we could hear the tantalizing sounds of the stream coming up from cracks and fissures in the floor). Anyway, we had virtually given up hope of finding the continuing passage, and had gone back to a steeply-sloping bedding-plane crawl of ~0.4 m high down which we?d slithered; to our astonishment, there was a near-identical bedding plane going back underneath the one we?d slithered down, with the draught coming out of it ? it was as though we had a metre-high bedding split in half by a thin, albeit extensive, slab of rock.
Anyway, we followed the draught up this bedding, which eventually changed back to a nice phreatic tube, and continued until we reached a sudden drop into very deep water, with limited air space, through which was roaring a howling draught. We dropped into the water and swam along a canal and across a lake to the start of a fantastic vadose canyon leading off into the mountain, at which point we deemed it politic to abort (there being only two of us), making plans to return the following day.
The next day we went back, equipped with a diving mask, as I figured that the sump was probably quite short after all; and so it proved to be the case. You then had the choice of a piss-easy free dive of less than a metre or a grotty crawl of over 100 m, but even if you were severely aquaphobic, there was no advantage to going the long way because you were up to our nipples before you?d left daylight, and in any case you still had the canal and lake to swim.
So, after exploring several hundred metres of fabulous river cave, we reached a chamber (maybe 20 m in diameter, 10 high) with the water flowing out of a sump. I?ve never been particularly enthralled by the appearance of the typical British sump, but this was something again, crystal clear water flowing out of a passage some 3?4 metres wide and obviously fairly deep; so, I figured I?d free dive it . . . far away from home, with no backup; I recall that I was the only member of the party who had an electric light, the rest being on carbide. So I took a deep breath and dived into the sump. I could see (with the face mask) airspace ahead, and surfaced in it, only to find that it was merely an air bell. So there I was, treading water (did I mention that the water was very cold?) and wondering how I could possibly have been so stupid!!! So far, so bad, but it gets worse. I took a deep breath and tried to dive back out, only to find that I couldn?t overcome the combined buoyancy of wetsuit and lungs to dive deep enough to get back; the roof of the tunnel sloped down, and I had of course followed this downward trend, then it rose suddenly, more or less vertically, into the airbell, and I simply couldn?t overcome this downward drop. I have a memory (from some 40 years later) of starting to calculate how much air there is in an airbell about 2 m in diameter . . . ? a sphere of radius 1 metre is 2/3 pi r3 . . . which is . . . oh, f*** it, I gotta get out of here!!!
I contemplated several possibilities, including dying; one idea was to strip off my wetsuit while treading water, and dive out without its buoyancy, and then dive back (or send someone else back!) with a rope to drag out the suit (so why, given that we had a rope, hadn?t I used it for some sort of diving line?). I didn?t really fancy that, then I had another idea ? expel all the air (or as much as possible) from my lungs, and dive out with reduced buoyancy. This I did, and landed on the right side of the sump, gasping for breath.