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Archive for the ‘Cave and Cavern Diving News’ Category






Valentines Tech Expedition: Cave Diving Thailand

Friday, February 19th, 2010

Technical divers explore caves and caverns in Thailand

khao-sok-cave-diving-thailand-17-300x225 Valentines Tech Expedition: Cave Diving 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.


Event - Cavern Diver Course Expedition Khao Sok - 2010

Sunday, January 3rd, 2010

Big Blue Tech will be conducting a 4 day  Cavern Course in Khao Sok National Park. The following dates are available.

January 3rd - 7th ( 4 spaces )

This trip includes the option of up to 10 dives.

This trip will be open to divers from around Thailand.

Pre-Requisites: Must be minimum Advanced with 20 dives ( Redundant Breathing System Provided)

Conduct: The course will be done on site in the national park over a 4 day period of 10 dives with academic plus dry land skills. Certification as a Cavern Diver will be received after completing 4 dives and a final exam with 6 experience dives to follow.

Included:
- Ferry to and from Mainland Thailand (if required)
- Transport to and around Khao Sok
- 4 nights accommodation in a 4 star resort inside the the National Park
- Manual and Certification
- All gas and cylinder fills
- All equipment (Reels, Torches, Dive Gear)
- All food and drinks (non alcoholic)
- Park Entry Fee
- Boat Fees
- 4 Training Dives
- 2 “fun” Experience Dives

Not Included: Beer

Tekkies: Technical gear is available for those certified, included in the course price.

Certified Cavern Divers:
For those certified we will be running exploration trips in conjunction with this course, this will allow certified divers to use the boat and compressor to conduct 4 days of diving

Gas:
Nitrox, Trimix and boosted oxygen available on site, on request.

Prices: 19,800 Baht


Event - Cavern Diver Course Expedition Khao Sok

Friday, December 18th, 2009

Big Blue Tech will be conducting a 4 day  Cavern Course in Khao Sok National Park. The following dates are available.

December 18th - 23th ( 4 spaces )

This trip includes the option of up to 10 dives.

This trip will be open to divers from around Thailand.

Pre-Requisites: Must be minimum Advanced with 20 dives ( Redundant Breathing System Provided)

Conduct: The course will be done on site in the national park over a 4 day period of 10 dives with academic plus dry land skills. Certification as a Cavern Diver will be received after completing 4 dives and a final exam with 6 experience dives to follow.

Included:
- Ferry to and from Mainland Thailand (if required)
- Transport to and around Khao Sok
- 4 nights accommodation in a 4 star resort inside the the National Park
- Manual and Certification
- All gas and cylinder fills
- All equipment (Reels, Torches, Dive Gear)
- All food and drinks (non alcoholic)
- Park Entry Fee
- Boat Fees
- 4 Training Dives
- 2 “fun” Experience Dives

Not Included: Beer

Tekkies: Technical gear is available for those certified, included in the course price.

Certified Cavern Divers:
For those certified we will be running exploration trips in conjunction with this course, this will allow certified divers to use the boat and compressor to conduct 4 days of diving

Gas:
Nitrox, Trimix and boosted oxygen available on site, on request.

Prices: 19,800 Baht


Courage required for Fiji’s famous limestone cave dive

Saturday, November 28th, 2009

420_sawa-i-lau-420x0-300x194 Courage required for Fijis famous limestone cave dive

To get to the inner limestone cave of Sawa-i-Lau, you must dive under a rocky curtain and swim through an underwater tunnel.

When the tide is high, both are under water and in pitch darkness. At less than high tide, the “curtain” is just a few centimetres out of the water.

It’s a dive into the unknown. You need a modicum of courage, as you scrape your head along the rock in the dark beneath the island opposite the village of Nabukeru, in Fiji’s Yasawas chain.

Two colleagues turn back. It’s too cold, they say. And they’re claustrophobic. But it’s only by visiting this inner sanctum, says the Fijian villager waiting for us inside, that you actually arrive at the heart of the Yasawas, the islands created by a dramatic fault that runs into the South Pacific on the north-western fringe of Fiji.

Only when you’ve visited this cave, says the villager, can you say that you have been to the Yasawas.

“This is the spirit of the Yasawa (singular),” says the villager, standing waist deep on a submerged rock.

It’s not completely black in the cave: there’s a vent dropping down on the way in, through the ceiling from the tall, rocky island above. But it’s black enough to make the nervous queasy.

You need a torch inside. The water is clear and, while not cold, it’s crisp, a degree or two cooler than the 26 degrees in the Pacific Ocean, which feeds the caves subterraneously.

The outer cave is a tall atrium. It’s well lit through its southern side, which is open.

The inner sanctum is very different. Most of the 20-metre long space is little more than a low gap between the sea water, at whatever the tide, and the limestone roof.

There is no sign of sea life in here, although the guide inside tells us there are small eels in there, somewhere.

This is our fourth visit to Sawa-i-Lau, but this time there is a big change up here, mirroring changes more broadly affecting the Yasawa, a pristine and geographically remote part of the world.

When we arrive in our runabout after a 45-minute voyage from Tavewa Lagoon to the south, we are greeted by Lucy, dressed brightly in a blue floral uniform, who introduces herself as our hostess.

Lucy herds us on the narrow beach and briefs us on the island and its dangers, such as slippery rocks on the water’s edge, and the low rocky overhang on the stairway down to the caves entrance inside the island. (”Drop your head: Don’t damage the rock,” says the sign at the entrance.)

Risk managers have been here, we think. On earlier visits, we had locals in stubbies and singlets take us into the rock, and that was it.

Their party trick was to clamber up the sheer rock faces inside the outer cave and plummet into the water, scattering the visitors bobbing around below them.

Now Lucy inducts us, like on a building site, then ushers us to the cave guides on the concrete stairs leading up to the caves’ entrance.

Those guides brief us again on the caves and their dangers, before directing us down the stairs to plunge two metres into the outer cave, where the water is around three metres deep.

The guides inside still plunge from great heights inside, to amuse the visitors, but the environment overall is much more controlled, more tightly managed, less spontaneous than it once was. (A gasp echoes around the walls as a reckless backpacker launches from the cave wall right below a local leaping from five metres above him. They land in the water in the same spot. Both surface.)

And they control access to the inner cave, allowing half a dozen at a time through the submerged tunnel. It’s more regimented and, in a litigious age, more professionally managed now.

There are four or five long, open tinnies visiting from the Tavewa lagoon down south, each carrying up to a dozen backpackers.

The journey up to Sawa-i-Lau has been fast and smooth, save for the final reach across a strait to the north of Nacula (Na-thewla), which is bumpy and wet, into a stiff nor’-easter and a heavy chop.

Our helmsman, from Joe’s Water Taxi, takes us directly across the channel into the lee of the northern shore, and along to the caves on the rocky island at the strait’s eastern end.

On the beach, Lucy moves from group to group delivering her welcomes and briefings with her soft, bright Fijian smile.

There are half a dozen women sitting in a line behind rugs spread in front of them offering souvenirs. We feel guilty that we don’t buy anything, but we’ve seen its like before. Most of the souvenirs look as though they’ve been shipped in from down south.

There are many other signs of progress around the Yasawas, an area known for its myriad budget resorts aiming at the backpacker and budget conscious traveller.

Atop Tavewa island, which forms the western boundary of the lagoon that bears its name, there is a telecommunications mast erected a year earlier by Fiji’s new mobile phone operator, Digicel.

The tower sits on the island’s peak, up a hill that is at times so steep that the locals have installed ropes to maintain traction on the hillside.

From the peak, there are panoramic views around the central Yasawa. The only sounds are the constant whoosh of the wind, and the beat-beat-beat of the wind fan which, along with solar cells, provides tower power.

Along with a primary tower on nearby Nacula, the Tavewa tower brings strong and reliable mobile phone reception and internet access to the central Yasawa.

We’re not pleased with this, but the locals are, not least because it makes communication with the outside world reliable.

Many local families have their kids away at school on islands down south, and resorts have offices in Lautoka, on the mainland.

And there are the employment opportunities. Locals were engaged to build the towers, and Api, who manages Otto and Fanny’s with his wife, La, Otto and Fanny’s niece, now has a second job in onsite maintenance for the two Digicel towers.

There are 17 resorts around Tavewa Lagoon, ranging from the up-market Turtle Island, a little to the south, to backpacker establishments such as Sunrise Lagoon, Safe Landing, Coral View, and Oarsman’s Lodge.

More budget-conscious than backpacker, Otto and Fanny’s, on the palm-heavy southern tip of Tavewa, is famous for Aunty Fanny’s afternoon teas (get ice cream with the cake of the day, alternately chocolate and banana).

Most of these cheaper resorts are not known for their food, other than in a negative sense, but Otto and Fanny’s turns that on its head: food is one of its strengths.

Otto and Fanny’s boasts Harry Doughty, Fanny and Otto’s son, a chef who has cooked at the resort for over 10 years. Harry’s food is sensational, particularly at the prices charged.

“Tonight, we are taking you to India,” says La, serving dinner on Tuesday. On Wednesday, it’s baked reef fish.

Unlike some of the other resorts, too, Otto and Fanny’s does not attempt to lock the visitor in to meal packages: you pay for what you eat.

If you don’t have lunch, for example, you don’t pay for it.

In the middle of the market in terms of price, a 1.7km swim across the channel from Otto and Fanny’s, is the stylish Nanuya Island Resort, with a dozen bures and another sensational menu.

There is vigorous competition amongst the Tavewa resorts, some gaining an advantage through a tie up with the provider of transport to the region, Awesome Adventures, which operates the daily Yasawa Flyer, a twin-hulled, high speed ocean-going ferry.

The voyage aboard the Flyer is an experience in itself. The four-and-a-half-hour trip north from Port Denarau snakes through the Mamanucas (Ma-ma-newthas), before crossing to the southern tip of the Yasawas, calling at up to 10 resorts on the way to Tavewa, two-thirds of the way up the chain.

The Flyer drops off and picks up backpackers, mainly, many of them on passes allowing them to visit multiple resorts over a week or so. (When you board the Flyer, head straight to the kiosk to get a roti parcel - curried potato wrapped in fresh naan bread: they run out early. And consider the Captain’s Lounge, which at $F20 one-way or $F30 return offers extra comfort, air-conditioning, and “hospitality”.)

The Yasawa is a beautiful, pristine, remote area. The water is clear and safe, the reef bright, varied and colourful, the air is clean, and a full day of swimming, diving, lolling about on the beach reading, village and cave visiting, leaves one ready to be sung to sleep by the lullaby of the sighing palms.

Source


Diving Sunken Villages in Thailand

Thursday, November 26th, 2009

 Diving Sunken Villages in Thailand

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


How Cave Diving Works

Friday, November 20th, 2009

cave-diving-6-300x199 How Cave Diving Works
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


CAVE DIVING: The Ins and Outs of HID lighting

Tuesday, November 17th, 2009

dsc_00471-300x199 CAVE DIVING: The Ins and Outs of HID lighting

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″).
(more…)


Sidemount: The New Revolution in Tech Diving Equipment.

Friday, November 13th, 2009

sidemont_positioning Sidemount: The New Revolution in Tech Diving Equipment.

sidemount_divers-300x218 Sidemount: The New Revolution in Tech Diving Equipment.

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…”


GUE Project: Discovering China

Tuesday, November 10th, 2009

rhea_gue_feb_09_0051-300x198 GUE Project: Discovering China

Two separate GUE scouting missions to Chinese caves in 2008 provide an opportunity to organize equipment, scout diving locations and develop community relationships. Unfortunately a November project is met with terrible diving conditions as heavy rains leave the caves undiveable. However, dry conditions eventually prevail and a GUE exploration team travels to China in February, 2009 to begin a detailed review of the region. The GUE team includes: Jarrod Jablonski, Casey McKinlay, David Rhea, Mark Garland, Gideon Liew and Andrew Cronan. The team is joined by David Deng from China and will focus upon outlining the complexity of the local caves in an attempt to outline realistic goals as well as necessary resources in the exploration of China’s massive cave systems.

Chinese government support, preliminary GUE success and a developing appreciation for the enormity of China’s massive cave systems encourage GUE to assemble a base of operations and a sustained series of GUE exploration projects. In addition to the unique potential for exploration, China is an ideal place to expand development of GUE Project Baseline. This conservation initiative calls for the development of local communities designed to support the long-term conservation of sensitive aquatic resources. The GUE team finds difficult conditions as they began documenting a complex series of massive chambers and remarkable dry caves. Preparations are underway for more extensive exploration in December, 2009 with a range of exciting developments detailed in an upcoming issue of Quest magazine.


Complex Cave Diving Navigation

Monday, November 9th, 2009

wyatt1-300x199 Complex Cave Diving Navigation

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)


Un-Reel Diving in Thailand

Tuesday, October 27th, 2009

khao-sok-cave-diving-cavern-thailand-72-225x300 Un-Reel Diving in Thailand

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.

khao-sok-cave-diving-cavern-thailand-10-300x200 Un-Reel Diving in Thailand

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.

khao-sok-cave-diving-cavern-thailand-52-300x200 Un-Reel Diving in Thailand

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.

khao-sok-cave-diving-cavern-thailand-39-225x300 Un-Reel Diving in Thailand

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.


Khao Sok Technical Diving Expedition

Friday, October 23rd, 2009

img_0161-edit-300x213 Khao Sok Technical Diving Expedition

Big Blue Tech will be in Khao Sok National from October 23rd to October 28th conducting technical diving, cavern diving and exploring new areas for yet another underwater village. This expedition will be combined with a TDI Extended Range and TDI Cavern Course.

In addition, Big Blue Tech will be on the new liveaboard vessel from October 27th to 29th installing a new continuous flow nitrox system.

During this time email and news might not be as forthcoming as expected. We apologize for any interuption in service.


Police Divers Go Underwater To Find Bodies and Evidence

Wednesday, October 21st, 2009

bilde-300x225 Police Divers Go Underwater To Find Bodies and Evidence

Most scuba divers would stay away from a sinkhole, but for divers at the Polk County Sheriff’s Office and the Lakeland Police Department, a sinkhole might contain the evidence needed to solve a crime.

Sinkholes, phosphate pits, gator-filled lakes - these are just a few of the places professional search and recovery divers are jumping into across Polk County. And all of them are dangerous. So dangerous, in fact, that search and recovery diving is the next installment in The Ledger’s ongoing series, “Out of the Cubicle: Dangerous Jobs in Polk.”

“It’s a series of challenges, from the diving to the environment, you encounter everything from microscopic germs to enemies as large as alligators,” said Brian Hanger, a deputy sheriff in the marine unit for PCSO.

Search and recovery divers often are called to the scene when a crime or accident involves a body of water. They recover evidence to solve crimes, bring a sense of closure to families who have lost loved ones in the water by finding bodies, and rescue fishermen on sinking boats.

Divers with the PCSO have dived about 20 times so far this year, and last year they dived about 80 times. The Lakeland dive team sees a little less action, with only a few dives per year. Each team has about eight divers.

To keep divers safe, each team trains regularly at different locations each time.

“We try to do a variety of things because Polk County has such a variety of lakes and we try to get people, when they are training, to keep in the mind-set that every body of water is different,” Hanger said.

The training is usually more diverse than normal sport dive training and focuses on safety. Training consists of learning how to communicate while under water, mapping out grids to perform evidence searches and learning recovery techniques.

An important part of safety is being able to communicate, Hanger said. Because of low visibility in the water, divers must learn to use different methods of communication, such as underwater headsets, because the normal hand signals most sport divers use cannot always be seen.

“When diving in the Lakeland area, we are lucky to see five or six inches in front of us because the water is so murky,” said Hans Lehman, the dive team supervisor for LPD.

The divers wear dry suits to protect them from exposure to any harmful bacteria or chemicals that may be in the water, especially in sinkholes and phosphate pits, Hanger said.

The extra-thick dry suits also protect the divers from puncture wounds from objects along the lake floors. The divers move slowly while underwater to avoid injury, Lehman said, but many discarded items serve as possible traps.

“Some of these lakes, you never know what you will find in them because people throw all sorts of stuff in there,” Lehman said.

“We have found everything from cups to plates to TVs to tires, refrigerators, engine parts and vehicles,” he said.

Not knowing what is lurking beneath the surface is often the most dangerous part of the job, Hanger said.

While diving in Lake Toho in Osceola County in an attempt to retrieve a firearm used in a crime, Hanger became entangled in fishing lures and lines and was unable to free himself.

But he was able to communicate with the other officers on land through the underwater communication system the dive teams use and they were able to pull him out.

“It took half an hour to cut me out of the fishing lines,” Hanger said.

Divers must also be aware of the wildlife in the water.

Lehman said alligators usually leave the divers alone, but the divers try to avoid night dives because alligators are nocturnal.

“For everybody’s safety, we will usually go in the daytime,” Lehman said.

The focus on safety for both teams has meant few injuries for the divers. In 13 years, Hanger could recall three injuries to divers, most of them minor.

“We’ve been very fortunate, but we’ve been practicing very good safety plans because we understand it is very dangerous and we take it very seriously,” Hanger said.

“As time has gone on we have focused on training, to keep us lucky.”


TDI Advanced Nitrox Completed - October

Monday, October 19th, 2009

advanced-nitrox-technical-diving-thailand-42-225x300 TDI Advanced Nitrox Completed - October

Today Big Blue Tech celebrated the successful completion of a TDI Advanced Nitrox Course for Ash, Matt and Andy.

The students come from different backgrounds and environments. Matt is a oil and gas worker based in Kazakhstan but frequents Thailand; he completed his SDI Solo Diver course last month and has come back for more serious diving. Ash is a Divemaster Intern with Big Blue and will soon move up to join Big Blue Tech in December. Andy comes from Denmark where he is actively serving in the Danish Army as a Sergeant and this is his break before returning home for overseas deployment.

The TDI Advanced Nitrox course is based on familiarity with technical diving methods and equipment, buoyancy, oxygen handling, mixes of nitrox above 40% and extended depth to 40m. Some of the highlights of this course included some wreck diving at Japanese Gardens, some cavern diving at Green Rock and diving with Bull Sharks at Chumphon Pinnacle.

Some of the students will continue on to Decompression Procedures which teaches the methods behind decompression diving and more advanced skills while others would continue to gain experience or return home.

In addition, Christos was awarded the TDI Semi Closed Rebreather rating after completing all the skills and requirements for the rebreather and accompanied the course for more experience and training on the rebreather.


Halcyon new Infinity BC System

Monday, October 19th, 2009

*Coming to Big Blue Tech in November 2009

infinity09-190x300 Halcyon new Infinity BC System
The most exciting thing to happen with BCs since the invention of the Scuba tank.
Halcyon Manufacturing is proud to announce our newest BC model, the Infinity ™. The Infinity’s most distinguishing feature is the novel harness adjustment known as the Cinch™. Our quick-adjust Harness (patent pending) redefines what it means to dive a backplate, providing unparalleled comfort and stability in a system with infinite adjustability. Unlike other designs the Cinch™ adjustment eliminates all quick release buckles and dangling webbing. This industry-first innovation marries the stability and streamlining of a backplate with the comfort and flexibility of a recreational jacket BC.
Key Features

  • Infinite adjustability in the blink of an eye
  • Snug, stable fit with easy removal
  • Easily adjustable while in or out of the water
  • Quick, easy fit is ideal for diver training
  • Useful for managing stressed or unconscious divers
  • Easily convertible for suits of varying thickness
  • Seamless use of weight pockets, canister light, hip D-ring
  • Includes Quick-adjust Crotch Strap
  • Deluxe shoulder/backplate pads for unparalleled comfort
  • Backplate pad contains pocket for lift devices
  • Comes standard with ACB10 Weight Pockets
  • Cinch adjustment can be used with singles or doubles

The difference between this and their other BCs is profound; there is a new adjustable harness which allows you to pull tight your harness. This lets you go between a wetsuit and drysuit without having to adjust those pesky belt slides. We got one as a demo in the shop recently, and we are very impressed with it. The cinch is tight enough that it won’t accidentally loose slack, but tightens with a quick pull. They’ve also created an adjustable crotch strap that can be lengthened or shortened in a pull. The harness has two other features worth mentioning; the left D-ring is on a fixed piece of webbing so it will stay stationary as you tighten the harness, and there is a buckle on the right side that serves to hold your canister light.

The new chinch harness is available in several configurations: you can buy the entire package with wing and backplate for 35,000 thb, just the harness pads for 4500 thb, just the cinch adjustment harness to upgrade your current system for $5000, or just the adjustable crotch strap for 2000 thb.

We are offering these online now as a pre-order. Halcyon has told us they expect to ship the first week of November, and we’ll ship pre-orders on a first come, first serve basis.


 


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