Volume 33 Number 1 Article 2
Exploring Khoh Al-Bidi -
The First Kilometre
The following article is by Eoin Mekie, an expat to Oman, and a friend of Tom Sykes. Eoin has kindly allowed us to publish this article which is an abridged version of the original. My thanks to Eoin for allowing us to publish this excellent account of cave diving exploration in the club newsletter.
The entrance to Khoh AI-Bidi lies some 50 metres up a boulder pile on the right hand side of Wadi Ghul, at the base of the 3000 metre Jebel Shams in Oman. The entrance leads into a short cave, at the back of which lies the sump pool. Access, especially with heavy diving gear, is difficult and requires a handline as everything must be manhandled in stages, firstly down a 2.5 metre drop then down a loose rocky slope and finally across a pool to the sump. Entrance to the main cave passage is via a narrow tube about one metre long and just wide enough to allow one fully laden diver.
The cave was first dived, as far as we can determine by Bob Hill and Dr Alistair Fraser of the Oman Cave Diving Group (OCDG). In atrocious visibility of less than a metre they penetrated some 25-30m into the cave, missed the main way on and wound up in a tight, tubular airbell to the left. This they aptly named the Smelly Airbell - perhaps unimaginative but very true. They exited, packed up their gear and vowed never to return.
Amazingly they were not the first people to pass the constriction and enter the main cave passage. James Laver, an engineer attached to the Omani Ministry of Water Resources, and a keen sea-diver, discovered the sump during one of his work related field trips in 1993. James was intrigued enough by the sump to return later armed with a single, front mounted snorkel! Not only did he snorkel the sump but he passed the constriction at -6m , entered the main passage beyond, saw what appeared to go on, turned and swam out - an incredible feat of breath holding stupidity. In his position at the Ministry he was one of the very few expats who had access to details of such watercourses. It was this finding that encouraged Bob and Alistair to visit the cave in the first place.
In October 1994, James persuaded Alistair to have another go and this time the visibility was much better. Thirty metres of line was laid across the first section of the main passage, by-passing the Smelly Airbell. Clearly the cave went on and a return visit to push further was planned.
Unfortunately, James lost his job at the Ministry and left Oman. This left Alistair with the difficult task of persuading Bob to have another go. A great deal of beer went into this effort, successfully and Alistair and Bob returned in November, this time extending the existing line from 30 to 100m, heading due north up the main passage. A second dive that day took me on my first visit to the end of the line with Bob.
A word about conditions. Visibility in Khoh AI-Bidi is never good, which occasionally stretched to 5 metres but is usually much less. Couple this with inexperience, a sea diving mentality (despite the twin independent gear), the use of small helmet mounted torches and home made line-reels and you get some pretty adverse diving conditions. Not surprisingly, initial pushes were deliberately short.
Enter Steve Dwyer, the fourth member of the team. With Alistair and myself unavailable at the time, Bob and Steve doubling the line laid to 200m - in our terms a great push forward! Growing in confidence and faced with an amazing opportunity to explore virgin passage, a more concerted effort was planned, this time involving the whole team. On 5th January, all four of us pitched up to make a determined push, if possible we would attempt to reach the half kilometre mark.
Up to the 200m mark the cave depth varied between 6 and 9m. However, after that it starts to undulate much more, at times large gravel banks and rock outcrops force you to within 3m of the surface. This is hell on your ears after a while. Forty metres further on we surfaced in the first of the large air filled chambers. Beautiful flowstones cascaded down the walls. The elation of being the first people ever to see this was simply gob-smacking. Towards the far end a steep gravel bank rises to within six inched of the surface, which must be climbed to reach the sump beyond. The air in the chamber is breathable but high in carbon dioxide.
Pressing on we reached the second slightly larger chamber about 60m further on. The chamber is of similar height and width but is 40m long and has a squeeze at water level about halfway along. From above the chamber outline looks like a figure "8". The squeeze can only be passed with difficulty, however it only extends for 2m below the surface below which it can be passed easily - yet another battering for the ears. Once again at the end of this chamber, a large gravel bank rise, this time to the surface. Doing this with twin cylinders on your back, breathing CO2 laden air will leave you quite breathless.
Here, at a distance of 330m from the initial sump we tied off and headed back, meeting Bob and Alistair in the first chamber. Unfortunately one of Bobs ears had succumbed to the incessant depth changes and would clear only with difficulty. Alistair went on to the second chamber then turned for home with Al blowing a sinus in the process. The first and second chambers were named Earbell and Sinus squeeze respectively, in their honour.
The full team returned, reversing order this time. Bob and Alistair went first making it past Sinus Squeeze and laying a further 140m of line to 470m. Steve and I followed reaching the end of their line and laying a further 95m, belaying off just below the surface of a long, lowish airbell. Surfacing to have a look I was stupid enough to remove my regulator and talk. Within three breaths I felt extremely dizzy, was developing tunnel vision and had a tremendous pounding in my head. I shoved the regulator back in my mouth and dropped below surface, signalling to Steve that all was not well. Within another 3-4 breaths I had recovered but felt extremely vulnerable. Meanwhile Bob had yet another bout of ear trouble, this time resulting in a reversed ear. Clearly, we were going to have to think carefully how to counter this problem. Not only that but Steve and I had reached the comfortable limit of thirds. To progress further we would need bigger [bottles] or staging.
8th June - we finally broke the 565m previous limit. Having decided that things were getting a little serious, the four of us persuaded the Cave Divers Association of Australia to lend us an instructor for the fortnight, in exchange for a holiday in Oman - they sent us John Vanderleest. After John spent a fortnight taking us apart and re-building us, we were in much better shape.. Suddenly, trim began to fall in place, finning, emergency and linelaying techniques improved and the general levels of confidence and competence went with them. Alistair, Steve, John and myself went back to Khoh AI-Bidi, the three of us determined to break past this mark. As well as the improved techniques John had taken our kit apart, trimmed it down, showed us how to reduce drag etc. and we were carrying some decent lights at last! In just over ten minutes Steve and I reached Sinus Squeeze. We pushed on quickly and in seemingly no time at all reached our previous mark at 565m. We hooked on the new line and started laying out. At 700m we came up into chamber No.3. This was bigger than both the other two put together - similar width but higher and longer, with a dog-leg to the right at its mid-point. The gravel bank here basically filled the chamber to the surface leaving us no alternative but to remove our fins and walk to the far sump. Not easy with twin 15's! From our last experience we kept our regulators in our mouths. About 20m beyond chamber No.3 we ran out of line, belayed off and set off for home. In all the dive took 1 hour 55 minutes, with 80 minutes underwater. The passage was still going, more or less due North with one or two twists and was getting shallower.
The only target now in our minds was the magic kilometre. The kilometre would mean planning on thirds - it needed a staged cylinder to improve the margins.
On the 22nd of June Alistair and I returned on a very hot and sweaty night. After portering in three cylinders each, plus our other gear, we were already exhausted. Slowly we put everything together, including the front mounted 7 litre cylinders which would provide us with the extra margins we needed. We set off down into the sump, through the constriction and on our way. To counteract the dry mouth effect we had reduced our Nitrox to EAN27 and were carrying drinks. We hung off the 7s in Earbell, then pressed on from there. Visibility was good, perhaps up to 7m in places. We passed Earbell then the old 565m point then came up into the third chamber. Here we had a drink then trudged along the gravel. The air was particularly foul, Alistair removed his regulator after walking through. Within seconds he felt the hypoxia symptoms, stuffed his regulator back in and fell forwards into the water. He recovered in an equally short time but it's a scary thought to know that if you don't get that regulator back in you could be dead very quickly.
I led off, reeling out into new territory. Visibility remained generally good - the passage still shallow, submerged but much more twisty that previously. Alistairs 100m of line ran out and we hooked up another 95m. At around 900m we hit chamber No.4. The water was about 18 inches deep throughout the chamber and we were just able to float through it. Beyond there the passage continued, shallow and narrowing twisting this way and that. Visibility deteriorated, making it harder to find the route. One or two places seemed to offer possible offshoots. The 95m ran out so we tied on our final reel of 50m. Eventually this too expired, leaving us at 1010m - the kilometre had fallen!
The passage continues, who knows how much further. We intend to find out. You may have guessed that Khoh AI-Bidi is not the real name of the cave. Anyone familiar with the major cave diving pushes of recent years will know where the name comes from. For reasons of discretion we prefer to use this alias, rather than the real name of the spring.