Technical divers explore caves and caverns in Thailand

Khao Sok National Park, Thailand - Big Blue Tech completed the cave and cavern diving portion of their expedition with the certification of a TDI Cavern Diver certification for Helen Artal, Thomas Hallstrom, Fanette LeGoarand and James Rickert during a 4 day/ 3 night expedition in Khao Sok National Park which hosts a man made lake with hundreds of undiscovered caves and cavern systems.

The course included all entry level skills including found in overhead diving including how to use a reel, deal with limited visibility and working as a team. In addition they also had to get used to fresh water buoyancy and diving in remote areas.

After certification the divers explored new areas and discovered some new caves in the 10 - 18m range which will be explored at a later date. On one dive a team covered over 1km of submerged limestone wall looking for caves.

On the final day the team departed from Khao Sok National Park and returned to Koh Tao on the 20th.

Technical Divers head to Khao Sok National Park for cavern and cave diving

Khao Sok, Thailand - Divers on the Valentines Tech Expedition leave Khao Lak for Khao Sok National Park for the overhead diving portion of the expedition which includes cavern and cave level diving.

The Rajjaprabha Dam (also called Chieo Lan Dam) was built in the 1980’s flooding the valley of large limestone cliffs creating a large man made lake. This lake submerged caves and caverns making it perfect for cave and cavern diving and cave diving training.

Also in this lake is a submerged village with a temple which was deserted before the flooding. This temple was discovered during a expedition by Big Blue Tech in June of 2009 - “Wat Lies Beneath”

Big Blue Tech will be in Khao Sok for 3 days and 3 nights before returning to Koh Tao. A full report and pictures will follow.

Divers train for a expedition for the month of February over valentines day.

Koh Tao, Thailand - Big Blue Tech started the orientation and introduction for 4 new students who will be working over the next few weeks to be trained as technical divers to depart koh tao on a technical diving liveaboard and cave diving in the Similan Islands and Khao Sok National Park.

The students consist of Duncan Tyler, Yvonne Fries, Helen Artal and Thomas Hallstrom who are all diving professionals. The course is being conducted by technical diving instructor James Thornton-Allan and assisted by future technical diving instructor Andy Cavell and Ash Dunn.

The goal of the next week is to certify the students for TDI Intro to Tech, TDI Advanced Nitrox, TDI Decompression Procedures and TDI Extended Range followed by TDI Cavern Diver and TDI Trimix.

While the majority of the training dives will be conducted in Koh Tao the team departs early in february to the west coast of thailand to board our liveaboard the Mv Pawara for 4 days and nights on the luxury vessel diving in Similan Islands we a few days in the end for some wreck diving and cave diving which builds from last months successful “Golden Horseshoe Expedition”

Today covered equipment organizing for all 7 technical divers and a refresher of theory with the introduction of technical diving specific information, the students were also tested on their water stamina with swim tests designed to ensure they have the basic fitness for the stress of this style of diving.

Our next expedition is planned for the end of February, to join or to receive more information you can contact us at info@bigbluetech.net

Technical diving and cave diving in Thailand featured in french magazine.

Koh Tao, Thailand - Big Blue Tech along with photographs from Christos Kardana have been featured in a 5 page spread in the french magazine Atacamag which can be read online through their website at Atacamag. Atacamag is an outdoor magazine which focuses on sports outdoors and interviewed Christos last year when they were travelling conducting research for their Thailand feature.

The magazine explores technical diving in thailand along with a focus on Koh Tao and cave diving in Khao Sok.

Follow this link to read a copy of the issue - ‘Atacamag - Numero 7‘

Technical divers travel north to dive with Manta Rays

Phi Phi, Thailand – Big Blue Tech departed from Phi Phi Island today to head back up to Khao Lak after it was decided that the island held no more interest for the team of technical divers.

Yesterday we dived in Maya Cave which was reported as a great cave worth a visit which we felt posed very little challenge and did give us a rush of adrenaline like other caves we have dived in during this expeditions.

Last night the team spoke with other divers on Phi Phi about the caves, the recreational divers who have never had any formal training in overhead referred to the other caves as “swim through”. This new information put doubt into our minds about the value of staying any longer in exchange for diving somewhere else. The decision was made to not go diving today and instead packed up and left the island.

Technical diving on this island as part of an expedition is very difficult to the point of frustration. We had major problems simply getting from one point of the island to the other with our gear let alone arranging boats and air fills. However it’s very unusual for a divers to travel through the country like this with their own equipment so it was not a surprise that we would encounter some problems.

While Phi Phi was great for a party and all normal holiday making and relaxing it’s a lot like Koh Tao in many ways but nowhere near as developed and established which could be a result of the Tsunami which wiped out Phi Phi island 5 years ago, an event which is remembered in subtle and respectful ways throughout the island.

Anyone wishing to visit Phi Phi should contact Susan at +66 0892894789 who arranged all the transport, accommodation and bookings really well over the phone and was essential to the modest success we got.

This evening the tech crew arrived back in Khao Lak where we would take out our speedboat for a couple days diving on the Similan Islands to look for Manta Rays. This is also the end of the road for Emily who returns to Koh Tao to get back to work teaching scuba diving at Big Blue.

Technical divers explore sea caves on Phi Phi Island

Phi Phi, Thailand - Big Blue Tech arrived in Phi Phi this morning to begin 2 days of sea cave diving in an attempt to clearly identify the caves in this area as potential for future expeditions.

Phi Phi island is best know for the location of “The Beach” movie starring that guy from Titanic. The story is actually based on Ang Thong Marine Park but they used Maya Bay to create the set for the beach.

Arriving on Phi Phi island we were surprised by how rural the environment is with no motorcycles or trucks to help transport equipment which meant the annoying task of humping all our gear along the pier to the small carts which would take us through the winding streets to Princess Divers who would host us for the next few days.

Once we were finally checked in to our hotels, sweating, irritated and hungry we had a small bite to eat and then set off on a long tail to Maya Cave which was reported as a stunning cave that goes in over 100m.

We found the cave quite easily with little reference and conducted one dive inside and it is not a cave it’s a cavern. It’s very hard to get into an area where you cannot see natural light. The size and design of the cave is also so vast that there’s really very little risk to call it a cave. However, you could get into a point where it’s linear depth is beyond 40m so in that respect it is a cave.

The large entrance leads to a huge cavern that is split in the middle by a pillar several metres across. The left side has a low ceiling 2-3m from the floor and has many interesting rock formations and stalactites, passing these the floor is littered with pieces of broken stalactites.

The right side past the split is more spacious with several metres from floor to ceiling but also with impressive stalactites. 100m from the entrance the two sides meet again at the back wall between huge stalactites.

There are more “caves” to check out but with the epic logistics and the utter emotional process to get to the dive site we just wanted to go back to our hotel and have a cold beer. Andy Cavell was more than happy to hear that as he was forming a speech impediment where every third word in his sentences was either “pub” or “pint”

Tomorrow’s plan would be 2 more dives at different dive sites reported to be good caves, hopefully we’ll find something to warrant the effort to get here.

Technical Divers arrive in Ao Nang resort town for deep fresh water cave diving.

Krabi, Thailand - Big Blue Tech arrived in the town of Ao Nang in Krabi province in southern Thailand today to set up a base for diving in Sra Keow Cave located in the jungle about 25km outside of Ao Nang Town which is reported to be 240m deep in a fresh water pool.

Sra Keow cave is clearly sign posted from the main road as a tourist destination in the region. During our initial visit today we saw many tourists enjoying the rope swing and swimming in the pool.

This resurgence fresh water pool has been explored by many divers in the past with some claiming to have reached a depth of 240m inside the pool which forms a cave. All this activity on the diving forums and in magazines and even then controversy over claims of who actually dived the disputed record breaking dive all lead us to want to check it out even more.

Although we’re conducting deep air dives to maximum 60m it will still be a good chance to check out this pool and see if it’s worth returning with trimix to explore further and continue to visit the pool in the future.

After checking out Sra Keow and other dry caves in the region we headed off to “One Stop” dive shop in Ao Nang where we met with Dave who works there. One Stop is the only distributor of Halcyon gear in Thailand and is very tech friendly. With a bit of shopping done and some logistics sorted for gas fills we checked into a hotel and relaxed for the evening with some starbucks coffee and Thai massage. The following day would be a great challenge both logistically and physically so a good nights rest was needed.

Tomorrow we would conduct 2 deep dives on site and then moving on to Phi Phi Island.

Ayesha Cantrell has written an article about diving in Khao Sok which features pristine caves and caverns with the lesser known feature of sunken villages, one of which has a submerged temple.

Ayesha  refers to the sunken village  we located and dived on earlier in the year, which you can read more about HERE and HERE

In one section Ayesha describes the environment perfectly in saying:

If you live in Thailand, working as a dive instructor, people think that you are constantly on holiday. Not so, and it’s good to get away once in a while, go diving somewhere else for a bit of fun, to see something different and keep island fever at bay.

Khao Sok National Park is as different as you can get from Koh Tao. The park is made up of thick ancient rain forest, calm and peaceful, with beautiful limestone columns towering out of the 165sq km lake that dominates the park. Most people go to trek in the jungle, spot wildlife and absorb the tranquillity, but a lake that large holds too much temptation for avid divers. This is where we go to chill out!

The rest of her article can be found on the DSAT Tec-Rec Blog

If you would like to dive on one of these sunken villages then you can join our monthly expeditions. For more info you can contact us at info@bigbluetech.net

Since cave diving is different from other recreational diving activities, many of the techniques people use are also much different. Divers are taught to swim in a prone, or face down, position, with the knees bent and the fins elevated above the plane of the body. This is mainly a precaution against kicking the bottom of a cave and stirring up sediment, but it also offers a good streamline and creates little resistance to the water.

Cave divers move about a cave by using a simple technique called “pull and glide” — using the tips of their fingers, divers look for crevices in rock for a place to hook onto. The rock is usually something hard and porous like limestone, so it should have lots of pockets and places to grab. After grabbing hold, divers pull and release, gliding through the cave with relative ease.

Cave divers learn how to use mostly their feet for directional changes along with short flutter kicks, and, in the case of solid limestone, some can push off a cave ceiling with their feet to propel themselves along.

Divers can also take along battery-powered diver propulsion vehicles (DPVs) to make swimming easier. Although there are many different types, tow-behind DPVs are the most common, which pull divers through caves. DVPs help divers use less oxygen since they’re not exerting themselves as much, and they can significantly increase the length of a dive.

Because there is little to no visibility in caves and cave divers must use their own source of light, guidelines must be placed to ensure people can find their way back to a cave’s entrance.

Most caves already have guidelines in place from past explorers — these are called “gold lines” because of their yellowish color. They consist of braided nylon string and are usually a bit smaller in diameter than regular rope at about an eighth of an inch. These are placed throughout the main tunnels of a cave. Labyrinthine caves also have smaller side tunnels, and these are provided with smaller, white lines. They don’t contact the main line; instead, they usually end within 5 to 10 feet of the main line.

The main line of a cave does not extend to the exit — this prevents open-water divers or untrained or uncertified people from viewing it as an invitation to enter the cave. Therefore, a main guideline typically starts 50 to 100 feet inside a cave.

Still, it’s a cave diver’s responsibility to run a temporary line, or entry line, along a reel from the outside of the cave in order to maintain a continuous guideline from open-water to the main line. This provides direct access to a cave’s exit. To make an entry line, divers make an initial tie-off to something sturdy, like a big rock. A secondary tie-off is also made in case the first one comes loose. The diver must be able to swim along the line with his hand around it, making an “OK” sign, and with his eyes closed make his way out of the cave. The line shouldn’t be run near obstructions in order to avoid snags and keep out of the way of other divers.

Dorf markers, or small, plastic directional arrows, can be tied to lines. These point toward exits, just in case a diver becomes disoriented. Clips, markers that resemble clothespins, are also used at points for notation reasons, including max penetration (the furthest point reached inside the cave) and points of interest for other divers.

The average cave dive will last in excess of one hour, but some can last for as long as 15 hours if the right equipment and gas supply is available. Divers generally use what’s called the “rule of thirds” — when one third of a diver’s air supply is gone, he will stop the dive and begin moving toward the cave’s entrance.

Source

by Marius Clore
Equipment and Technology Chair, NACD

Cave diving is critically dependent on lighting, hence the absolute minimum requirement of one primary light and two backup lights. The primary light must be sufficiently powerful both to signal appropriately and to view the cave, while the backup lights, which must be very reliable, need be only sufficient to follow the guideline out of the cave.

The advent of HID lighting has led to considerable improvements in both the quality of light and burn time over the older halogen lights. HID stands for High Intensity Discharge, and HID bulbs consist of two electrodes a short distance apart in a gas-filled chamber. A high voltage (low current) pulse across the electrodes creates an initial spark that results in the formation of a small plasma arc which produces a very broad band of high intensity light extending from the infrared to the ultraviolet.

In this brief article, I will summarize the basic features of HID lights, and compare HID lights in the 18/21W range from a number of manufacturers, including Salvo, Halcyon, Dive Rite and Sartek (see Table for summary of features and specifications).

In terms of components, an analogy between a HID light and a tank and regulator is useful. Every HID light comprises a battery canister, a battery, a ballast and a light head which are analogous to the tank, air supply, regulator 1st stage and regulator second stage, respectively. It is also worth considering that HID light usage should be considered in the same vein as air usage. Just as one turns a dive on 1/3rds, one should never plan a dive where the total possible duration of the dive is going to exceed half the burn time. Moreover, one should be conservative in this estimate since, in contrast to one’s air supply where one has a direct read out of remaining air pressure, it is impossible to know exactly what the total burn time is going to be, since this is obviously dependent on how well the battery has been charged (see below).

Given that HID lights are built from standard components, the variations in design are rather limited, and consequently, the choice of light is to a large extent a personal one based on preferences relating, for example, to the size of the canister, the packaging of the light head and the materials employed.

The canister. The canister should be robust and water tight. Salvo and Halcyon use Delrin, Dive Rite uses PVC and Sartek uses acrylic. Delrin is a more reliable material under extreme conditions, is not susceptible to cracking when dropped, and doesn’t become brittle in extreme cold. This may be important when diving in the Arctic, but under the environmental conditions found in Florida and Mexico, there is little to distinguish between the three materials. The dimensions of the canister are governed by the choice of battery pack configuration. The dimensions of the Salvo and Halcyon 9 Ah canisters are identical, while Dive Rites’ is wider, and Sartek’s is both wider and shorter. Indeed, the dimensions of Dive Rite’s wreck canister is the same length as the Salvo and Halcyon’s 13 Ah canister and only minimally narrower (3.5″ versus 3.75″).

The batteries. Modern HID lights are generally powered by nickel metal hydride (NiMH) rechargeable batteries. NiMH batteries provide the same energy (measured in Wh) as lead acetate batteries in a much smaller package (about half the weight and size for equivalent power capacity), they have a relatively long life with no cell memory, and withstand high charge/discharge currents. Generally, the nominal voltage of the pack is 12V and the total energy is given by the capacity in Ah times the nominal voltage. Thus a 9Ah 12V battery pack has a total energy of 108 Wh. If the ballast consumes 24 W (for an output of 18 W dues to losses), the total burn time can be estimated at 4.5 hours. However, the capacity of NiMH batteries is usually 10% lower than the rated capacity, yielding an actual burn time of about 4 hours. A 9 Ah pack can be built from either twenty 4.5 Ah 4/3 Fat A batteries comprising two strings in parallel, each comprising 10 batteries in series which easily fits into a 2.75″x10.5″ canister, as in the case of the Salvo and Halcyon lights. Alternatively, a more reliable pack in terms of obtaining a full charge (see below) can be built from a string of ten 12V, 9Ah D batteries in series, but the dimensions of this pack are quite a bit larger and can therefore only fit in either the 13.5 Ah Salvo and Halcyon canisters (3.75 x 10.75″).
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Sidemounting traces its roots to the UK, where cavers would strap small air bottles to their thighs, enabling them to traverse sumps — short, water-filled passageways that connected air-filled chambers, often far into a cave. Cave divers in the USA began adopting sidemount in the early 1980s, as a means of passing through bedding planes — cave passages that can be several feet wide, but only a few inches high.

Among the earliest adopters of sidemount in the USA were Wes Skiles and Woody Jasper, who recognized sidemount as the best way to explore cave systems such as Cow Spring and Jug Hole. (You can read more about the early exploration of Cow Spring on the NSS-CDS website.)

The rigs created by these early cave explorers differed from those employed by their British counterparts in that the cylinders used were substantially larger, and the divers wore them under their arms for better balance and body position. Still, until the mid-1990s, any sidemount rig you saw was going to be homemade.

Things started to change in 1995, with the introduction of the Dive Rite Transpac. Shortly after its introduction, Dive Rite’s Lamar Hires began offering a variety of hardware solutions designed to help users adapt their Transpacs for sidemounting. Still, in many respects, these solutions were only slightly removed from their homemade predecessors.

The real sidemount revolution began ten years later, with the introduction of the Dive Rite Nomad, a ready-made, out-of-the-box harness designed specifically for sidemounting. Simply stated, the Nomad changed everything.

Prior to the Nomad, sidemounting was seen as solely for cave diving, and solely for those few cave divers who “pushed” the tightest of passageways. With the Nomad, sidemounting became mainstream — something that any cave or technical diver could adapt to, and something with benefits that went far beyond cave diving.

* With the diving population’s aging comes a realization that prancing around in heavy, backmounted doubles may not be the healthiest thing past your 50th birthday. When the possibility of back, neck, knee and ankle injuries increases, it’s time to look for alternatives.

* Sidemount divers don’t have to wear their tanks to the water. You can carry cylinders to the water’s edge, one at a time — or roll them there on a standard hand truck.

* Sidemount provides true redundancy, free from the worries associated with catastrophic manifold failure.

* Without the manifold constantly hitting you in the back of the head, you can actually look up and see what is going on in front of you.

* For traveling technical divers, sidemount means they no longer have to be hampered by the lack of manifolded doubles at their destination. As long as there are single 80s available, tech diving is possible.

* Harnesses like the Nomad also offer an excellent solution for rebreather divers. Technical rebreather diving requires that users carry one or more open-circuit bailout bottles. By mounting their rebreather on a harness like the Nomad, rebreather divers have a means to carry those bottles in a way that is both streamlined and efficient.

No good deed goes unpunished. As validation of its concept, Dive Rite now finds competing sidemount harnesses made by Golem, OMS, OxyCheq and others. On the flip side, sidemounting has been recognized as a an alternative tech and recreational configuration by agencies ranging from the NSS-CDS to PADI.

PADI course director Jeff Loflin now offers a PADI distinctive Specialty Diver course for recreational sidemount diving, along with a corresponding distinctive specialty for instructors.

Despite its growing popularity, sidemounting is not a panacea.

* You most likely don’t want to jump off a dive boat with high freeboard wearing sidemount — nor do you want to have to worry about getting back on board. (Sidemount may, however, be the better solution for diving from inflatables.)

* When diving in places like the caves of Mexico’s Yucatan Peninsula, backmount is better suited for passing through the narrow openings between stalactites and columns.

Still, interest in sidemount is growing, by recreational and technical divers alike. In fact, there is a joke circulating in cave country about the veteran diver who shows up to dive with a much younger buddy. Looking over this elder’s highly Hogarthian doubles set up, the younger sidemounter remarks, “DIR? That’s so 90s…”

Complex navigation in the cave environment is critically important. Taught at the Apprentice Cave Diver level, it is further refined at the full Cave Diver level. At the Cavern and Basic/Intro Cave Diver levels we discourage complex navigation and train divers to stay on the main line. No jumps, no circuits, and no traverses. Cave diving fatalities have occurred when team members mismanaged complex navigation and lost their reference to the direction of the exit.

Skill Review

In the last couple of issues of the Underwater Speleology I have reviewed “How to” scenarios: How to relocate a lost buddy and how to relocate a lost guideline. I encourage you to re-read those articles with special attention paid to the primary sources of trouble: lack of awareness in the cave, failure to use a continuous guideline, and the direct link between increased task loading and decreased awareness.

The modular programs in cave training take advantage of compartmentalizing chunks of training and, by design, save complex navigation for the latter half of training. The reasoning for this is that the task loading cave students undergo at the cavern and basic cave levels (things such as how to properly deploy a reel, buddy awareness, line awareness, overall situational awareness, and dive technique) should be mastered and in muscle memory before more complex dive plans are made and students begin using one third of their gas supply for penetration.

Plan Your Dive

Once a dive plan is made that includes jumping off of the mainline onto another line, the following procedures help the team stay focused on the task of more complex navigation and helps prevent them from “going the wrong way” during their exit.

Divers should always run a reel to the main line and for all jumps. Proper directional markings are essential for safely navigating to the exit. Relying upon memory or someone else is not the safe way to do this. In low or no visibility we realize that it is very easy to become disoriented and go the wrong way.

Dive Your Plan

Once in the cave at the agreed-upon jumps, one teammate designated to install the jump reel should locate the line they are jumping to. He/she should deploy the jump reel, tying in to the other line, to make a continuous guideline back to the exit. The other teammates should wait on the mainline providing light for the teammate deploying the reel, as well as verifying that the jump is done correctly.

Most popular jumps have double line arrows indicating both that a jump exists in the vicinity and indicates the nearest exit direction. If there are no arrows on your jump, place one that can be identified as yours by sight and touch once you return to that line/jump point. Once the designated teammate installs the jump reel he or she will OK the other teammates with his or her light and only then do the other teammates cross to the new line. Once crossed the teammates should inspect the tie off also inspect the reel to ensure they can identify it as their team’s reel once they return. Reels should also be prepared in such a way that they can be identified by touch.

The team is then safe to continue into the cave until someone turns the dive and the team begins its exit. At this point the team’s approach to safely navigating out of the cave is critical, partially dependent upon how the jump line was initially installed and marked.

Safe Exit

After the team turns the dive and once the team reaches the point where the jump was made all teammates, except the team member running the reel, cross to the other line and wait for the reel person on the exit side of the jump. This helps set up the proper exit direction and the proper team order is not changed.

The person responsible for pulling the jump reel should wait at the reel and ensure his/her teammates have each made the jump and are waiting on the exit side before untying the reel from the line. Once all teammates are on the exit side the team member managing the reel can remove it.

Low- or No-Vis Exit

This method is relatively simple and works very well in good visibility. If the team is exiting in low or no visibility the reel(s) should just be left in place. These procedures help ensure that each teammate is thinking about the navigation and is not just following another teammate. Each cave diver is verifying and validating this phase of the dive, as they must also be doing during all phases and transitions during the dive. — Text by Jim Wyatt (photo by Jill Heinreth)

Big Blue Tech has recently returned from cavern and cave diving in one of Thailand’s National Parks called Khao Sok. Big Blue Tech conducted a TDI (Technical Diving International) Cavern and Extended Range course for Matt Payne, Mike Borneo and Ash Dunn. Matt and Mike who had already completed their Advanced Nitrox and Decompression Procedures with us earlier in the year returned to join this expedition with Ash Dunn who will be joining the tech crew in December as our new facilities manager.

The 4 day expedition in Khao Sok proved to be a text book adventure of challenging dives in stunning surroundings. On this particular trip the water had risen another 5m making the sunken temple out of range for the 55m certification depth.

The increase in water level on the lake was a result of heavy water fall leading up to the trip. Thankfully the rain fall and preceeding weather didn’t effect diving conditions or underwater visibiility leaving nothing but clear skies and sunshine.

The expedition progressed with the required training dives for the Cavern Diver certification followed by exploration for new cave systems and accelerated decompression dives up to 55m.

The students were introduced to new and unfamiliar conditions with diving from a longtail and in fresh water. While most chose the more formal method of backwards roll, others like United States Marine Captain Mike Borneo chose a more uncoventional method.

One of the more interesting highlights of the caverns was the exploration of a dry pool above one of the systems where a dive could surface to see the stalagtites and stalagmites forming above. An interesting spectacle when all the dive computers registered that we were still at 4m while very clearly above the surface of the water.

As the trip concluded, the divers had experienced 10 fresh water dives and combined their previous training with the challenges of overhead environment.

Big Blue Tech would like to tank Prival Raft House and Big Blue Diving for their support and assistance conducting this expedition.

Big Blue Tech returns to the region for more diving in December of 2009.