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Christos Kardana’s Technical Diving Photography Gallery

Friday, December 4th, 2009

Semi-Closed Rebreather Diving

Christos Kardana, former tech crew member of Big Blue Tech has put his photo’s online on Flickr for everyone to see.

The majority of his work was composed during diving trips with us to Khao Sok and other diving destinations we ventured over the past 6 months.

On his website he describes his method by saying:

“Utilising multiple cylinders and mixed gas blends, technical diving allows you to dive beyond the standard recreational range. Characterised by extensive equipment requirements, added redundancy and decompression procedures; technical diving allows for exploration of deep water environments, wrecks and caverns.”

His collection can be seen HERE


OMS PROFILE SIDE-MOUNT SYSTEM

Wednesday, November 25th, 2009

In 2010 Big Blue Tech will begin distribution of the OMS Side-Mount System called the OMS ‘PROFILE’. Big Blue Tech saw this system first in February of 2009 while it was being trialled in the caves of Khao Sok National Park by one of it’s developers.

Along with the release of this new system will also be in the introduction of Side Mount courses including cavern, cave and technical diving specific course for the Side Mount popularity.

Side mount systems have been growing but because of problems importing the products to Thailand it has been difficult to get the market leading manufacturers products causing a slow reaction to this growing trend.

The official details can be found on the OMS website;

This system has filled a void and will offer the “at home” and traveling diver freedom from the weight concerns of handling “back mounted” doubles. Side-mount allows individuals with limited physical abilities and lower back issues to enjoy the redundancy of two tanks and two regulators by minimizing the amount of weight on the lower back and lowering the center of gravity for increased stability when entering/exiting the water. Additionally reaching behind your head to shut off or turn on your manifold valve is a thing of the past as both cylinder valves are near your hands. Traveling divers can relax knowing that easily available single tanks are all they need to enjoy redundancy and adequacy of gas supply for any dive around the world.

    Features:

  • Allows the diver to utilize most harness and wing systems (with standardized 11 inch O.C. hole spacing)
  • Over the shoulder design keeps the wing close to the divers back and allows air to travel freely from divers left to right
  • Integral bib adds over 1/8” inch of abrasion protection to the vulnerable top part of the wing
  • No changes to the fit of the harness throughout the inflation of the wing from empty to full capacity
  • Permits the Rebreather diver to back mount the CCR scrubber and side mount the Oxygen and Diluent cylinders
  • Enables the diver to back mount the bottom gas and side mount the decompression gases
  • Streamlines the diver allowing access to tight, remote, hard to reach caves and wreck passage ways.

Below are some pictures from the OMS Website about the new product.


‘Big Ocean - Big Breath’: The Art Of Freediving

Thursday, October 22nd, 2009

freediving-apnea-thailand-3-300x232 ‘Big Ocean - Big Breath’: The Art Of Freediving

by Christos Kardana

For us divers, being underwater makes complete sense. Abandoning life as we know it and descending to the depths, we find a sense of gracefulness, motivation and challenge. We can direct all anxiety and attention to our feelings inside, whilst reflecting on the beauty and allure of the ocean. All the above hold true, but as I hang off my reel line at 6m completing my last ceiling stop of a recent 50m technical dive, I catch a glimpse of a figure ascending from depth and suddenly I don’t feel very graceful anymore. Adjusting my buoyancy to compensate for my bulky twin set and deco. cylinders, I watch the figure surface; he is cool, calm and collected, preserving the only air he has with him-that in his lungs. He is a freediver.

The art of freediving, or apnea diving, has existed for some time now, the roots dating back to thousands of years with the hanyeao Koreans collecting shells and sponges and the Japanese ama divers searching for pearls. In the Mediterranean, spear fishers, would dive with bated breath hunting for grouper and octopus, forming the historical basis of the apnea sport itself.

Using no breathing apparatus whatsoever, freedivers seem to defy the constraints of the underwater world, by descending dozens of metres, in many cases beyond the limits of an average scuba diver. The potential anxiety of not having enough air to re-surface and the general idea of no redundancy equipment available – as customary in technical diving- in case of emergency is an intimidating concept for me. It’s surprising, that in an extremely physically demanding environment the key to successful apnea diving is relaxation, security and of course concentration.

In the past, scientists believed the chest would collapse at depths greater than 38metres (115 feet), a figure crushed regularly by today’s apnea divers. The human body is resilient indeed, and certain adaptations stemming from the mammalian dive reflex, enable our body under diving conditions to endure depth and lack of oxygen. As you descend, bradycardia kicks in, dropping heart pulse rate up to 7-9 bpm compared to the usual 70 bpm associated with a person at rest. Vasoconstriction (shrinking of blood vessels) directs blood away from the limbs for benefit of the heart, brain and lungs. Oxygen rich blood cells are released (splenic contraction) and when atmospheric pressure crushes your lungs to the size of a melon blood shift ensures capillaries in the lungs swell with blood and reduce residual volume. Without such adaptation, permanent damage would occur, with the human lung shrinking excessively and wrapping into its walls.

“Relaxation and concentration is important” These are the two main elements to a successful freedive according to Jeroen Maertens – freediving instructor at Big Blue Diving, Thailand. “It’s about pushing yourself beyond the urge to breathe” he says. Interesting indeed, the concept is almost inconceivable to me.

When I decided to join Jeroen for an apnea course in the warm waters of Koh Tao, I found the whole approach quite difficult to imagine. Despite my sheer fascination with the sport and the concept of challenging myself an exciting one, I still wondered how anyone could truly enjoy themselves whilst diving down a line to reach depth. Either way, I was on the course. Jeroen is an intriguing character; softly spoken, tall and slim with rugged face and long hair; he is reminiscent of the old freedivers I would watch diving down for octopus, as a child growing up on the island of Cyprus.

After a few videos displaying the remarkable efforts of record-breaking apnea divers such as Herbert Nitch and William Trubridge, he explains the various disciplines and styles:

Constant Weight Apnea where the athlete has to dive to the depth following a guideline that he or she is not allowed to actively use during the dive.
Constant Weight Apnea Without Fins follows the identical rules as Constant Weight, except no swimming aids such as fins are allowed.
Free Immersion Apnea is a discipline in which the athlete uses the vertical guide rope to pull him or herself down to depth and back to the surface.
Variable Weight Apnea is a record discipline that uses a weighted sled for descent. Athletes return to the surface by pulling themselves up along a line or swimming while using their fins
No-Limits Apnea is a record discipline that allows the athlete to use any means of breath-hold diving to depth and return to the surface as long as a guideline is used to measure the distance. Most divers use a weighted sled to dive down and use an inflatable bag to return to the surface
Static Apnea involves motionless breath-holding at the surface and finally Dynamic Apnea; involving breath-hold diving for horizontal distance rather than vertical depth.

Jeroen emphasises meditation and guides us through breathing cycle techniques, highlighting the importance of a three compartment inhalation i.e.: sticking out the stomach, then expanding the rib cage on either side and finally filling up your chest, in an attempt to fully maximise our air intake. I try it a few times with my shirt off staring down at my stomach trying to emulate Jeroen. He takes 5-6 seconds for each compartment with pauses in between simulating a balloon inflating to capacity. My attempts are not so good; as I try to complete the cycles I end up more out of breath than when I started and exchanging looks with Jeroen we start laughing as he assures me it gets easier with time. “I hope so”, I say as we grab our equipment and make our way to the boat.

We arrive at the dive site, a beautiful bay on the west coast of the island; the water is calm and cool and Jeroen sets up the descent line and float, while I practice some shallow duck diving. Jeroen dives down, to examine the line barely exerting himself as he drops to the bottom. As I watch him with my face in the water I look around; the seabed has a nice glow and a small shoal of damselfish are already aggregating around the weights at the end of the line. Jeroen returns to the float, calmly looks at me and says “Ok, your going to do 6 breath cycles, take one deep breath, relax and pull yourself down the line. You can make it to the bottom and back easily, I promise” Yeah right, I thought starting my breathing cycles. Finally I take my last breath-the time had come-I open my eyes and let my weight pull me down, trying to stay focused but remembering everything Jeroen has said on the surface. Suddenly, at a mere 7 metres, I have to turn round; I feel like my lungs are going to explode and as I bolt to the surface I think “ there is nothing relaxing about this”. Jeroen looks at me while we hold on the float bobbing with the waves.  “You have more than enough oxygen to get to the bottom of the line and back with no problems” he says “It’s just about relaxing and going beyond your comfort zone. When you feel like you need to turn around, DON’T and don’t be alarmed by the strain on your body, your diaphragm might contract, just ease into it.” I start my breathing cycles again, closing my eyes, rocking with the water, I suddenly feel at peace. I inhale one last time and grab the line. Upside down, I am hypnotised by the line running through my fingers. When the first stirrings of the urge to breathe hit me, I look down and the end of the line is so close I can touch it. I carry on but with a slight panic in my movements. I touch the end of the line and rotate my body preparing for my ascent. Suddenly, my chest contracts and I feel a sense of euphoria. By my side at all times, Jeroen looks at me and motions his hand in a manner as to say, its normal, your doing great” As I break the surface, I have some recovery breaths and then pause, realising I am not starving for oxygen at all. I feel completely placid. It’s a profound moment as I realise one breath is more than enough; its just about learning to utilise it the correct way, not just letting it exist in the way we are accustomed to: a lifetime of stress and pollution, taking our shallow little breaths for granted. Jeroen looks at me, “well done, that’s 14 metres, tomorrow you will go to 22.” Despite my personal achievement of the day, this seems a dramatic increase, but by the following morning Jeroen had me practicing breathing techniques based on pranayama yoga (much like that utilised by renowned freediver Umberto Pellizari), and before I know it I was at 22 metres, crystal clear water above me, circled by curious barracuda and I realise I have discovered a new lifetime hobby.

To know that you can keep swimming even after your body demands more breaths from you, and achieving calm and serenity whilst doing this, is unlike any feeling I have experienced previously as a recreational or technical diver. Conquering my fear was not as hard as I initial anticipated and it really is about concentrating on your breathing and rejecting all of your body’s over-practiced urges and impulses. The result is senselessness and peace, participating in the surreal workings of our body and acting as a wondrous silent observer of the open ocean…


Drager Dolphin Extreme - Semi Closed Rebreather in Thailand

Friday, October 16th, 2009

drager-dolphin-tdi-rebreather-semi-closed-extreme-backplate-19-300x225 Drager Dolphin Extreme - Semi Closed Rebreather in Thailand

Big Blue Tech have been rebuilding a Drager Dolphin Semi Closed Rebreather in an attempt to create a Semi Closed Rebreather that functions and resembles the Halcyon RB80

The Drager Dolphin SCR always had some draw back that kept it from being respected amongst the more adventurous divers:

1. The in water trim was terrible;  The breathing bag or counter lung was located in the top of the unit and the steel cylinder slung in the bottom which made the diver very vertical, almost like a baloon with a weight tied on to the bottom. Additionally the bail out cylinder was mounted on the side making it unbalanced even if you did get vertical in the water.

2. The blue “Commando” bcd wasn’t black.

3. The white box that held the breathing bag wasn’t black

4. The small steel cylinder wasn’t big enough and a larger cylinder would only make the unit worse.

5. There was no way to mount deco or stage tanks.

6. The BCD was restrictive and could not be used with a backplate and harness.

Our initial purchase of a used unit in thailand gave us everything we would need including the oxygen sensor for our pp02 display. Out of the box, the unit was working perfectly with all the tests passed and no leaks.

Our first goal was to remove the old and restrictive built in bouyancy compensating jacket to allow the installation of a backplate and wing mounting system. This mounting system from V4Tec would allow all technical diving backplates and wings to be fitted in the same manner you fit diving gear to twin tanks.

The mounting system and side by side tank brakets arrived and fit perfectly. This alteration improved trim, bouyancy immediately. With the twin 6Lt (S40) cylinders mounted side by side it was difficult not to be balanced and horizontal.

The final and most dramatic improvement was the flexible manifold. Contacting our friends in Pattaya who own an engineer shop, we were able to source the high pressure hydraulic hose along with the fittings for our cylinders. This would give us redundancy and increased gas volume. We would still carry a bailout but that could be slung from the harness.

The testing later moved into shallow water trials where different divers of different skill levels went for a short dive to test the trim and overall experience. While this would be their first time in a rebreather they found it quite easy to reach neutral bouyancy and effective trim. The divers practiced bail out techniques  and general rebreather loop use.

Open water ocean trials will be conducted in the near future to test exposure limits and functionality in saltwater.


 


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