On the 4th September 2012 I embarked on a ten day, zero to hero cave diving course, taught by TDI Stage Cave Diving Instructor, Craig Werger of Ban’s Technical Diving, Sairee Village, Koh Tao, Thailand. The course comprised 21 training dives and 2 fun dives, which took place at three sites in southern Thailand: Khao Sok National Park, Song Hong, a sinkhole near Thung Yai and Sra Keao, a cave system near Krabi. The entire experience was, simultaneously, one of (if not the) most challenging, yet rewarding, diving experiences of my life and has left me with a wholly new appreciation for diving as a sport as well as my own personal limits.
All dive courses start with a text book and this course was no exception. What was exceptional, however, was the quality of TDI’s manual, Diving in Overhead Environments: Your Complete Guide to Cavern and Cave Diving, by Richard Dreher. The 160 page volume is clear, concise and introduces all relevant topics, from the history of cave diving and the types of cave, through to proper equipment selection configuration, dive planning and a detailed breakdown of the skills required to become a safe cave diver. Key concepts are obviously highlighted and there are frequent diagrams and photographs, although these are only in black and white. Nonetheless, the content more than adequately prepares you for the individual course exams and develops the vital knowledge base which underpins the practical part of the course. As manuals go, this one is a good one. People do not take diving courses to read, however, so after a few days absorbing the literature I was keen to get down to some practical work.
The trip began with a team session of checking our gear and packing the truck. Ban’s Technical Diving provide all specific equipment, however bringing as much of your personal gear as possible is recommended as long as it is suitable for cave diving. This pre-trip session was a good opportunity to discuss equipment suitability with Craig and ensure everything was in good working order. After a few hours the truck was packed and later that night we boarded the night boat to Surathani with 4 twinsets, 10 deco cylinders, a compressor with spare engine, fuel, emergency oxygen, all our personal gear and four cheery divers. Half a days driving and we arrived at the Khao Sok National Park ready to begin cavern training.
One of the fundamental tenets of overhead environment diving is the maintenance of a continuous guideline to open water. As such, the Cavern course began with an introduction to the use of reels, the tie-offs used and the protocols for running and following a guideline, in the form of an informal practical workshop in the restaurant of our resort. After an instructor demonstration, each of the participants took turns at primary, secondary, standard and final tie-offs, along with how to follow a guideline in zero visibility, through the use of touch contact. This early introduction of performing skills blindfold was to set a precedent for the entire course. The afternoon brought my first experience of the overhead environment diving in a cavern called Red Cave. The two dives were the realisation of the pre-dive guideline workshop and a chance to deploy our newly learned line skills in the real world. The choice of site was ideal. Red Cave is comparatively shallow, allowing for a safe training environment, yet yields a true cavern experience, with its impressive stalactite formations. These were no fun dives, however, and the deployment, installation and blindfolded following of the guideline, along with some basic safety skills, challenged the abilities of the group considerably. Any ideas about an individual’s diving prowess were quickly shelved as each student realised the challenge that lay ahead. After each dive Craig gave a relaxed, yet comprehensive and highly informed debrief. Day two of the Cavern course, provided a similar experience, this time at The Elephant’s Belly, but developing the skills of the previous day further. We were introduced to zero-visibility out-of-gas drills and the necessary techniques for maintaining team and guideline contact at all times, thus ensuring a safe exit from the cavern even under the most undesirable of circumstances. The Ban’s Technical maxim of “Train hard, dive easy” was put into full practice.
As we moved onto the Intro to Cave course, we were introduced to line markers, permanent cave guidelines, lost diver and lost line drills and further touch contact communication. This took the increasingly familiar format of a pre-dive workshop in the resort restaurant, in front of an audience of bemused Thai locals. The Intro to Cave dives were spread out over two days and took place at two locations: Peter Cave and Red Cave (this time beyond the natural light zone). Many of the skills were development and practice of the key skills learned in the Cavern course. The two notable exceptions were the lost diver and lost line skills. The former turned out to be a reasonably simple affair of deploying one of your two mandatory safety spools, attaching it to the primary line along and conducting a search pattern. The latter proved to be one of the most psychologically significant challenges I have ever faced underwater.
The lost line drill is a skill on the Intro to Cave and Full Cave courses and, as the name suggests, is designed to teach you how to locate the main guideline in the event you lose contact or sight of it. The skill began with Craig signalling for me to turn my mask around and use the neoprene strap to blindfold myself, a now familiar occurrence. He then takes you away from the main guideline and spins you in all orientations. He then leads you to a hard surface and you are then responsible for finding your way back to the guideline and identifying the correct exit direction. Step one is to deploy a safety spools to establish “a point of lostness”, from which you then conduct a loop shaped search pattern, first swimming down, then across and finally up, in an attempt to catch the main line in your loop, all without any visual reference. The initial step of finding a tie-off, seemed very simple in the pre-dive workshop. In the water was a different matter. I cannot tell you how unsettlingly disorientating it is to lose all your visual sense underwater. Even without a mask, you can see an astonishing amount. In the total darkness of the cave, with only your fingers and ears to guide you, you situation becomes lonely quickly. The wall I had been placed on felt as smooth as a mirror and as wide as an ocean. I groped around, for seemingly a very long time, until I came across a minute, hook shaped formation, which felt wholly unsuitable for a tie-off but was better than nothing. I tied off and conducted my three searches into the darkness, along what I felt were correct patterns, only to return each time to my initial tenuous point. The disorientation is impossible to underestimate and I quickly became frustrated. Perseverance paid off however and on the fourth attempt I found the guideline and correctly identified the exit direction. Mask replaced and big knucks from Craig and my elation was formidable. As a single skill performed, the lost line drill has showed me what can be achieved when one truly focuses their mind on a task. Cave training has shown me that sight, whilst a marvellous luxury, is by no means a necessity for survival and this, I am certain is down to the tutelage of Craig and Ban’s Technical.
The remainder of my fives days at Khao Sok were spent, starting Full Cave, which further builds upon the first two courses, but adds complex navigation, circuits, traverses and jumps and gaps, with regular dive planning discussions and pre-dive skills workshops. The culmination of this being a traverse at Temple cave, taking time, after much zero-vis skills practice, to enjoy the hugely impressive, bright white flowstone, often called draperies that can be enjoyed in this cave. The final dive at Khao Sok introduced restrictions and how to deal with, you’ve guessed it, loss of visibility and out of gas scenarios. The image of a diver crawling through a narrow, silted out passage with the sound of cylinders grinding against the ceiling, is the classical interpretation of cave diving and I was relieved to find that I found it an exhilarating test, but one that by this stage of the course I felt adequately prepared to undertake. As always each dive was succinctly debriefed, highlighting both positive points and areas for improvement, cultivating an analytical and progressive approach to diving practice. I left Khao Sok in high spirits.
Our next destination was Song Hong, an innocuous looking pool, located near the unglamorous village of Thung Yai. The calm, green surface of the water, set in a small wooded area gives no indication of what lies beneath it. Song Hong is in fact a sinkhole that descends to almost 200m and has 20m, 30m, 40m and 50m survey lines, a traverse to a smaller, adjacent pond with a maximum depth of 43m and numerous lines which direct a diver to some seriously deep water. Most of the dives are spent underneath an vast ceiling hovering over a tremendous expanse of black water below. Song Hong is truly epic and it was here that I was to finish Full Cave and Stage Cave.
These were to be big dives: a circuit on the 30m line and cleanup to complete Full Cave and then on to Stage Cave. Stage diving involves the use of an additional cylinder of bottom gas to increase the range of penetration into the cave. As such the first dive in the course was a skills dive to review the handling of the three S80 cylinders I would be carrying, in addition to by backmount set and a range of skills regarding the staging and retrieval of cylinders on a guideline. These skills were done with and without both visibility and gas and a hairy combination of the two: a breath hold swim to a staged cylinder, which had to be utilised as a gas source and retrieved, all without being able to see. In addition to these skills, we also practised out of gas drills with stages and buddy breathing exits. This went far beyond the minimum standards of the TDI Stage Cave course and one really felt that value for money was certainly attained. The following dives were two dives of a complex circuit on the 40m line, with planned bottom times of 40 minutes. As a further extra curricular activity, the team would be deploying a new line measuring tool, in order to collect survey information for the production of a map. Yet again an indication that this course was about educating cave divers as opposed to ticking boxes on a list of key standards. The ultimate dive at Song Hong was the traverse from little pond to big pond, which leads to the 40m line, allowing us to use information from our previous circuit dives to ensure sufficient gas for a safe exit. With a single file descent down a narrow cave passage, complex navigation and a 90 minute run time, all brought together with coherent and efficient team communication, this really was the crowning glory on a spectacular course.
The final dive of the trip was a fun dive in the Sra Keao cave system, near Krabi. This is a very narrow cave passage, accessed from a murky looking pool, which can be dived, single file, to a depth of 250m. Our plan was to do a bounce dive to 55m with a conservative ascent. Krabi had been on the receiving end of a lot of rain, so, when we arrived at Sra Keao, the water was very high and the visibility in the pool was practically nil. Regardless, we geared up in the hope that the vis would clear up as we progressed deeper. As we entered the water the vis was worse than we’d imagined and it took us a good ten minutes to located the main guideline and start our descent. As we descended, we angled ourselves forward to match the steep angle of the cave passage and to avoid disturbing the sediment. This proved to be a moot point as the visibility remained consistently abysmal. Contact with the guideline was required at all times and if you were luck you might catch of glimpse of the diver’s fins in front of you. At 40m, with no improvement in visibility, the decision was made to turn the dive and we began our ascent. All gas switches and decompression stops were managed in the reduced visibility and in a strange way I actually found myself enjoying the dive. Being at 30m, in decompression, in a tight flooded cave, with no visibility might be some divers’ idea of a nightmare, but as a result of the training I had just undergone I felt quite at home. It was by no mean ideal conditions, but was certainly no cause for alarm. Such is the value of proper cave training.
The learning curve from open water technical diver to cave diver is biblically steep, but thanks to the professional, yet still very approachable instructional style of Craig Werger and Ban’s Technical Diving this proved a more than manageable and enjoyable journey. The variety of sites and additional skills and discussions provided an extremely broad introduction to the new world of cave diving. At every step, safety and an adherence to standards was practiced as was an continually analytical approach to diving, which I hope will make me a more thoughtful and progressive diver and has absolutely provided me with the skills and knowledge to be a safe cave diver. Cave diver training with Ban’s Technical has proved to be one of the best decisions of my life and I would recommend it to any diver with an interest in accessing the overhead environment in the safest manner possible. It’s a no brainer: Sign up now!
Howard “Hugo” Angel
TDI Stage Cave Diver
PADI Tec Deep Instructor