The Deepest Scuba Dive - Part 1

CREDIT | Text Karen van den Oever | Photos Supplied

Breaking the Woman’s World Record for the Deepest Scuba Dive has been a personal goal since 2004/2005 when Verna van Schaik and Nuno Gomes respectively broke the female and male world depth records. Since being a member of the Wits University Underwater Club at the time, I was fortunate to have the opportunity to get to know both Verna and Nuno.  Their achievements were huge motivation and inspiration for the attempt on this world record.

I started technical diving under the tutelage of Nuno Gomes at Wits Underwater Club and continued to develop as a technical diver. After leaving Wits Underwater Club, myself and Francois Bain, my now husband, started our own dive club/ dive school called Somewhere Out There Diving. The idea of Somewhere Out There Diving was to create a business entity for the purposes of out of the ordinary, expedition type diving trips and this married up splendidly with the technical diving endeavors that have been embarked upon as part of the lead-up to the world record attempt.

I started SCUBA diving in 2001 and proceeded into the realm of technical diving in 2006. I gradually and progressively built up experience and skills to the extent where I felt that I had become sufficiently competent and comfortable to attempt the Women’s world record for the deepest SCUBA dive.

Depth Training
Initially I started training and building up depth experience in the ocean at Sodwana Bay, Kwa-Zulu Natal, South Africa and was able to reach a depth of 140m there. I soon realized that going much deeper was going to be too dangerous and logistically very challenging given the conditions of the South African coastline.

The only other alternatives were Komati Springs and Boesmansgat, which are inland, freshwater venues. I therefore opted to continue my experience in Komati Springs, near Badplaas in Mphumalanga. With each trip going a little deeper until I eventually reached the 150m mark in the inclined shaft of Komati Springs. Komati Springs is an old flooded mine, with underground workings which make it the perfect deep-water training venue.

As I was gaining more experience and knowledge from completing these dives my sights slowly shifted to Boesmansgat, a water filled dolomitic cave, situated near Danielskuil, Northern Cape Province, South Africa. I had never been there before and had heard and read plenty of stories of how logistically challenging it is to dive there. I had to see for myself.

Evaluating the Dive Site

In April 2019 a small group of us ventured to Boesmansgat for a long weekend. The plan was to drive there on Friday, do some planned dives on Saturday and Sunday. Then return to Johannesburg on Monday. Upon arrival at Boesmansgat, I soon realized that diving here was not going to be easy. Just getting equipment to the water was a colossal task and, on that particular weekend, we had very little equipment compared to what was to come. Over that weekend I managed to do one 40m dive and I was not convinced that diving deep in Boesmansgat was a good idea, but, since there was no other option, I had to accept that it was to be the venue. If I was to attempt it at all.

Thereafter the preparations really stared. First up was plans for a 200m dive. My idea was that the 200m dive went well I would only then put final plans in place to attempt the world record. I realized that I needed a bigger team, the small team of support divers we had for the Komati Springs dives was just not going to cut it at Boesmansgat. The team slowly started to expand. At that time, still a lean team but eventually I had enough support divers to make an expedition to Boesmans possible to do the 200m dive.

Team Building

To hone the team, we spent many weekends at Komati Springs doing work up dives. The team needed to work well together. Everyone needed to understand what was required of them and what they would need to do in the event of an emergency situation. In Feb 2020 we embarked upon a full expedition to Boesmansgat with the intent for me to do a 200m dive. The dive went off well and I successfully reached 200m. Plans were then set in motion for the world record attempt.

The idea was to do the World Record Attempt on the Women’s’ Day Public Holiday on 9 August 2020, but then the Covid-19 pandemic hit. South Africa went into hard lockdown at the end of March 2020. Our plan was put on hold, with things only starting to become more open towards the end of August 2020, we had missed the opportunity to do the record attempt and since the entire team had not done any serious diving for several months, we were forced to start build up dives from scratch. So back to Komati Springs it was for the team for a number of weekends. By January 2021 we felt that myself and the team were ready for the world record attempt and the final arrangements for an expedition in March 2021 were made.

Workshops and Planning sessions
In preparation for the various excursions, and particularly for the world record attempt expedition, we needed to look at all eventualities.  Several technical diving workshops were held where various aspects of the plans were discussed. As a team we did a full risk analysis, putting mitigation plans in place for every conceivable risk we could think of. We also needed to put emergency plans in place.

One of the biggest challenges we faced was how to we get a diver out of the “gat” and back to the cars in an emergency situation. Since the “gat” or water level is situated about 40m below the level where the cars are parked, down about 150m of scree slope and rocky terrain, this was by no means going to be an easy task!

We looked at every possible option. The simplest and quickest solution would ordinarily be to pull the person up the cliff face in a Stokes basket. None of us were competent climbers and we did not have all the required equipment to do this nor were we trained to use all the equipment that would be required, so this was not an option. We eventually settled on the reality that the team would have to carry the person up all the way from the bottom! Not necessarily the quickest option but the safest for all parties involved.

Practicing Emergency action
We did a dry run of this in the days leading up to the record attempt. the team managed to get a diver out of the water and up to the medical station, we had set up, in 17mins. It would take us a further 5 mins to get from the medical station to the cars/recompression chamber. Which is actually pretty quick if you look at the terrain they had to tackle while carrying someone in a stokes basket. What was of particular assistance is an extendible aluminium ladder which Jan Vorster had brought with. This was laid at an angle over the most severe boulder areas and acted like a set of rails which the stokes basket, with the diver inside, could be pulled up and over. Once at the top of the ladder section, the ladder was lifted and moved to the next tricky section, sequentially, until we had passed the boulder section. This made the herculean task of carrying the potentially injured diver a little more manageable.

The Chamber
We would like to make a special vote of thanks to Michael Partridge for bringing along his one-man recompression chamber and setting it up – we had the comfort of knowing that there was a chamber on site and ready for use, should we need it. Thankfully it was not required during the expedition.

Equipment considerations
Due to the difficulties in getting cylinders to the water and back up and out of the “gat” again we needed to think carefully about how we were going to blend gas and fill cylinders on site. It is challenging to blend gases in the field. To minimize what we needed to blend on site, many of the cylinders were pre-blended at home in Johannesburg before the trip.  Then they were transported to the site. The again meant that we needed a lot more cylinders and suitable vehicles with trailers to transport them!.

We set up a blending/filling station and medical station halfway down to the water, on a recreational platform area built by the farmer. Only the few stage cylinders that absolutely needed to be refilled with either Nitrox or Trimix would then be carried back up to this point, filled, analyzed and then carried back down to the water’s edge again. Apart from some of my shallower gasses for the world record dive, most of the gas blending done was for the *diluent cylinders, for Peter Reid’s rebreather, which were actually quite small. (*Rebreather has two cylinders.  A pure oxygen cylinder and a diluent cylinder. The diluent cylinder will have a gas mix suitable for the maximum depth of the dive. Oxygen is added to the mix in the mixing chamber to keep the gas at a selected partial pressure at all depths throughout the dive.)

Carrying up twin cylinders each time they needed to be filled, was not going to be possible. We set up a 75m long high-pressure hose that would run from a compressor at the top of the cliff, to reach all the way to an area, which we had identified as the twinset refilling area, in a cave near the water’s edge. This worked well and we were able to fill all air cylinders without having to carry the heavy equipment back up to the top. Since this was done in a dedicated area, the possibility of a clutter of empty and full cylinders in the vicinity of the entry point into the water was avoided.

Air Fills
With huge THANKS, the task of filling cylinders was made much easier with the Coltri MCH16 ERGO 315 lire per minute compressor, graciously loaned to us by Coltri South Africa with the assistance of Steve Moller.  This really helped with all the airfills that needed to be done and divers could get back into the water much faster.

Mother Nature
In the weeks leading up to the Boesmansgat 2021 expedition, we were alerted to the fact that the Danielskuil region had experienced extraordinary high rainfall in the preceding months. Severe flooding had occurred a few weeks prior to the trip and the water level of Boesmansgat was rising at a rate of knots. We knew that space would be limited for setting up a staging area at the water’s edge and had to revise our plan carefully. The dive team was alerted of this fact and everyone was informed that just the bare essentials would be permitted to be brought down to the bottom of the hole. Careful consideration was also given to which areas around the waters edge would be used for what purposes in order to maintain a neat and ordered dive site and operation.  

Dive site Entry area organisation
There was a designated area for full twin sets and an area where empty twin sets needing filling were to be placed (near the filling end of the 75m long hose) and a stacking area for full stages near the entry point was agreed upon. These cylinders were covered with a shade cloth tarp. Empty stage cylinders were provided a separate area, until they could be carried out of the hole, either for refilling or storage topside.

Oxygen and more Oxygen
On any technical diving expedition, having an abundance of oxygen is very important. We needed to make sure there was enough oxygen at the water’s edge for all the divers to use during their deco stops. And more than enough to be used in the event of an emergency. We decided to set up an “oxygen tree” in the water, as each of the divers would need oxygen to deco on during all of the buildup dives. The support divers would need oxygen to do oxygen deco on the record dive. For these reasons we used a 50 Litre bank cylinder, that was placed at the medical/blending station, to feed oxygen to the divers at 3m in the water. We installed a very long high-pressure hose that was attached to a 50 litre oxygen bank cylinder and ran from the medical/blending station about 150m down the slope into the water. This was attached to a block that we could connect three demand valves to and was placed in the water at 3m. This meant that there was a continuous supply of oxygen for divers to use and we did not have to worry about constantly carrying oxygen cylinders back and forth to be filled.

Doctor in the House
Deep diving comes with risks. There is always the possibility of something going wrong and we needed to be prepared for this. Because of these risks we had a diving physician on site to deal with any life-threatening situations, should they occur. Thanks to Michael Partridge and DAN Southern Africa we had Lt .Col (Dr) Rob Bedford, who is the Chief Flight Surgeon and Second in Command at the Institute for Aviation Medicine in South Africa, in attendance on this expedition to treat any medical emergencies should they have arisen.

Before any divers could enter the water, we need to place a shot line into the cave. This line would serve two purposes: one as a guideline for all divers entering the cave and secondly this would be the line where all stage cylinders would be hung for the deep dives. This line was securely tied around a boulder outside of the water, with a secondary line attached using a piece of static line also securely tied around a boulder, to ensure that in the event that the first tie off came loose for any reason, there would be a second tie off/line securing the shot line to the surface.

Once all the logistics had been addressed, all emergency equipment was in place, the chamber was tested and up and running. And all team members had arrived, the record dive attempt was a go, we were all set.

NOTE:  This is the first in a series of Articles written by Karen van den Oever about how she and a team of dedicated scuba diver went about making the extraordinary deepest scuba dive world record by a female dive.  PART 2 To follow soon.