Phuket Thailand Rebreather Diving and Draeger Dolphin Training

Dear fellow diver,

Welcome to a new millennium. One of the most dynamic trends in the new millennium will be the way we breathe underwater.

Semi-closed Rebreathers for recreational divers are here to stay supported by PADI’s training programs for the Draeger Dolphin and Ray units.

Enriched Air Nitrox has already proven to be a great asset for the recreational diver.

Maybe you ask yourself: “Why bother with all this rebreather stuff?” 

The answer is simple. If you want to go face to face with timid marine life for an extended period of time, without annoying bubbles, rebreather diving is for you.

Dolphin - The secret of silence

You dive into the water and in an instant you are in a different world. Stress, noise and the hustle and bustle of everyday life suddenly seem far away. You become one with the silent world and are acutely aware of your senses. No noisy valves, no hissing air, no annoying air bubbles - nothing. Even the ordinarily shy inhabitants of the sea are hardly bothered by your presence. And you are free to enjoy the fascinating feeling of being an accepted guest. For the first time you can experience the silence of the silent world.

You are diving with a rebreather -the Dräger Dolphin. This semi-closed rebreather allows you to experience diving as never before. What is special about rebreather systems is that your exhaled gas is not released into the water as in conventional open circuit systems, but is purified and returned to the breathing circuit. As a result, you can enjoy your dive to the fullest - not only a longer dive, but also a completely undisturbed adventure.

Dräger Dolphin - a quite new diving experience

The Dräger Dolphin removes carbon dioxide from the exhaled gas through a sodalime cartridge and then channels it into the inhalation bag, where it is enriched with fresh Nitrox from the supply cylinder.

This constant supply of fresh gas ensures that you will always be provided with enough oxygen. If, however, you should need more gas - for example if you are subjected to great physical exertion or you wish to clear your mask - a bypass valve opens automatically to supply additional fresh gas. For very shallow breathing - for instance if you are "lying in wait" for a photo opportunity - the circuit opens and small air bubbles escape almost silently through the positive pressure valve behind you.

Another aspect of rebreather diving you will enjoy is that the inhaled air is pleasantly warm and moist. This is because the chemical reaction involved in the absorption of carbon dioxide generates warmth and moisture, and as a result even ice diving can become a real joy.

As a result of optimal reuse of the exhaled gas, your gas consumption drops by up to 90%, meaning that the Dolphin's 4 or 5 liter cylinder can last for a whole weekend of diving.

Nitrox - it's the mix that makes the difference

The Dolphin uses Nitrox, in other words a nitrogen-oxygen mixture. Nitrox offers you a new range of diving. With Nitrox your breathing air contains less nitrogen, and you can stay down longer, because the non-decompression times have been increased. Say, you are diving up to a depth of 20 meters. Compared to a conventional non-decompression time dive with compressed air, Nitrox 50/50 enables you to stay under water more than 3 times as long.

How long you can dive, how often and how deep - with Dolphin this is all a question of the mixture. The variable oxygen-nitrogen mix ratio gives you enhanced capabilities. Extra training is essential though, to ensure that you learn how to take full advantage of these possibilities. We will be pleased to give you the training.

So why to use a Rebreather?

Divers, over the years, met and solved many problems. Drysuits and quality wetsuits made it possible to keep cold further at bay, and larger and higher pressure cylinders encouraged dive times of one hour and more. The advent of dive computers took much of the complication out of repetitive diving by making decompression calculations more straightforward, whether the diver wished either to make simple precautionary stops or more formal exposures.

The development and acceptance of enriched air NITROX diving offered longer and potentially safer dive times. But the amount of open circuit SCUBA equipment necessary to make most of this is too bulky, heavy and awkward for the average diver, making the extended dive time offered by NITROX a choice between submerging not only under water, but also under a massive pile of equipment! Open circuit SCUBA is also noisy and uncomfortable, the exhaust bubbles scare wildlife and interfere with vision, and the weight of equipment even makes getting in and out of the water inconvenient - and does little for the health of the diver's back!

Enter rebreather like the Dolphin lightweight, portable, simple to use, it revolutionizes NITROX diving. Extending dive time to up to ten times that offered by a conventional open scuba cylinder at normal work rates, reducing bubble noise to an absolute minimum (and hiding those few bubbles behind you), it allows you to get closer to marine wildlife (did you get this, photographers?), it allows you to pack hours of weekend diving into the boot of a car or the cabin of a yacht without having to wonder where the next air fill is coming from, and it allows you a freedom of access to the underwater world that you only hitherto dreamed of. It allows you to rediscover the sea down to 40 meters!

Utilization of breathing gas

Compared to the normal use of compressed air, NITROX breathing gases in a rebreather system has a much better utilization of breathing gas. With compressed air on a 20 meters dive we will have a utilization of 1.3%, the rest with 98,7% is lost. With a NITROX 50/50 dive at the same depth we will have a utilization of approx. 35%, depending on the work of breathing. If we go deeper we will also have a higher utilization with NITROX.

No decompression time

Most of the recreational divers are diving between 15 and 25 meters. Divers want to lie at the Great Barrier Reef at 15 meters to observe the underwater world and have the feeling of being with Captain Nemo 20.000 leagues under the sea.

NITROX gases will bring a great advantage to such dives. Depending on the choice of gas mixture, you will have longer non-decompression times, as with traditional compressed air. You will have the possibility to dive up to two hours at 20 meters without any decompression time. The limitation in this case is only the NITROX cylinder of the Dolphin with 4 liters and 200 bars.

Diving profile

A dive to a depth of 20 meters using compressed air, compared to the use of NITROX with 50% oxygen and 50% nitrogen, explains the big difference.

A non-decompression dive with a NITROX of 50/50 will extend the duration by more than 100%. Total duration of 40 minutes with compressed air will be increased to approx. 110 minutes with NITROX 50/50. A dive on 30 meters with decompression and a NITROX of 40/60 will impressively increase the bottom time and require a remarkable shortened decompression time.

Temperature of inhalation gas

When we compare the inhalation breathing gas temperature and open circuit system and rebreather, we will notice a real difference, which allows us to dive with a rebreather in January in the North Sea without a freezing regulator. The heat generated in the scrubber canister causes this longer thermal balance.

We can further influence the inhalation breathing gas temperature with an insulator or a heater. But these solutions are being better applied in the field of commercial and military diving.

Different Rebreathers

When we talk about Rebreathers, we must differentiate between four types of rebreather. Closed circuit and Semi-closed circuit systems and pure gas, pre-mixed and self-mixing.

  1. Oxygen Closed circuit rebreather
  2. Closed and self-mixing rebreather
  3. Semi-closed and pre-mixed       rebreather
  4. Semi-closed and self-mixing       rebreather 

Oxygen closed circuit rebreather

The exhaled breathing gas is cleaned in a closed-circuit system through a sodalime cartridge and is enriched with oxygen supplied from a cylinder carried by the diver. This apparatus is completely bubble-free with low gas consumption. The operating depth is limited by the use of oxygen.

Therefore we do not use the oxygen rebreather for recreational diving, because we cannot limit the sports divers to a maximum depth of 7 meters. We all know our friends - if they discover something interesting in the underwater world they will go deeper.

Mixed-gas rebreather

Mixed-gas closed-circuit diving apparatus facilitates long and deep diving operations. It operates as a Semi-closed circuit system with pre-mixed gases or a self-mixing system.

Low gas consumption, safe decompression, longer no-decompression time, silent and less bubbles, ... are only some advantages of Rebreathers, which recycle the exhaled breathing gas with a sodalime canister.

Depending on the gases used such as NITROX or HELIOX diving depths up to 100 meters are possible. Specific features for special navy operations are provided in this apparatus, which should not be, confused with mixed-gas closed-circuit diving apparatus for sports divers. At first we will open the recreational diving market to Rebreathers with a system for use in the shallow water range up to 50 meters. When this have been done in a safe way we will then be in the position to concentrate on the next step - to go deeper or to use self-mixing systems.

SOURCE: DRÄGER

To learn more about the Rebreather Training with IDC Phuket, please utilize our inquiry form.

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