Connect with us

Thai Life

Phuket Diving: Re-breather revolution



PHUKET: The pool is silent. Three divers, but not a sound. Then, right before our ascent, we flip the switch on our regulators to open-circuit. There is a roar of bubbles that destroys the silence – it’s inappropriate. Yet in reality, up until my recreational re-breather “Try Dive”, a cacophony of bubbles ballooning in my face was all I had known.

Almost every diver in Phuket, indeed the world, took their first precious underwater breath on what is technically known as an open-circuit configuration (what you most likely think of when you think of scuba diving equipment).

Even catchy slogan, such as “Take only pictures, leave only bubbles”, was derived from the bubble blowing on an open-circuit system, which expels “used” air out into the environment. But for years, tech-divers have one-upped the recreational crowd with re-breathers, often through necessity, with “Take only pictures, leave no sign….”

Silently going on deeper, longer dives was the draw and is still the draw for using a re-breather. They have been an essential tool for many tech-divers in exploring and discovering previously unknown parts of the underwater world. And this year, that same opportunity for exploration has come to the forefront of the recreational diving scene.

The Poseidon MKVI, known as the “world’s first re-breather for recreational divers”, and the launch of PADI’s first recreational re-breather dive course are opening up entirely new aspects of dive sites. The simplicity of the system allows nearly any recreational diver to make the plunge into the re-breather world.

Admittedly, in the pool session of the “Try Dive” run by re-breather instructor Kevin Black from Kiwidiver there wasn’t much to explore: blue tiles, clear water, four walls… and yet it was exciting.

A re-breather triples your dive time. In many ways it’s like having a nitrox blender on your back, perfecting the oxygen content in the air you are breathing at any given depth. It is this efficiency that allows for longer, deeper dives.

Diving at Shark Point for a second time, there will no doubt be an array of stunning new moments. However, the path that you take, and the sea fan with the sea horse hidden nearby, will most likely be the same.

The re-breather is assisting recreational divers down different paths – same dive sites, different dives.

“An example is Koh Doc Mai. You can go off the northern end of Koh Doc Mai where there are several pinnacles at 30 and 40 meters that are fantastic to explore. There is a huge amount of marine life on them and no one ever goes there, because we can’t on an open-circuit system,” Kevin explained.

A chance to dive sites that have as yet been mostly inaccessible to recreational divers isn’t the whole package though – remember the silence?

“There is no intrusion on the marine life. So they tend to go along with their business and you can get right up close as they are not scared of you,” explained Kevin after the pool session.

“We miss 90 per cent of the marine life because it’s hiding from the noise, and until you dive on a re-breather and hear how noisy open-circuit divers are – you just can’t understand it,” he added.

The most elegant example can be seen in the footage of two of the greatest divers of our century, the world-renowned Jacques Cousteau and the first “modern” underwater photographer, Hans Hass.

Both have excellent footage (for their time) of sharks. However, Cousteau, who was diving on an open-circuit system, depicts an animal that appears nervous, while Hass’ footage, silently captured while diving on a re-breather, is able to embody the calm beauty of one of the ocean’s most enigmatic creatures.

How does a re-breather work?
In an open-circuit system, the air that is exhaled at a shallow depth has only used up about a quarter of the oxygen; the remaining oxygen, along with nitrogen and carbon dioxide, is bubbled out into the abyss. Because none of the inert gases (nitrogen and carbon dioxide) are used and only a fraction of the necessary oxygen is used, it is estimated that 95 per cent of exhaled breath from an open-circuit system is wasted.

A re-breather is a closed system, so the air exhaled is kept in the system.Used air runs through a hose to the bottom of a “scrubber”, which, with the little heat and moisture from a divers breath, causes a chemical reaction that absorbs the dangerous carbon dioxide and leaves clean air ready to be re-breathed. If such a cycle continued with no input, the air would eventually be devoid of oxygen, so the recreational re-breather will mix either compressed air or pure oxygen from two small cylinders on your back into the mix in order to create the optimal air for breathing at a given depth.

The history of re-breathers is rife with horror stories, many derived from divers not packing their scrubbers properly, causing “carbon dioxide hits”, where carbon dioxide rich air is breathed in by a diver, to devastating ends.

Now, however, with the Poseidon MKVI, all scrubbers are pre-packed, and ready to go. In addition to this safety precaution, a computer analyzes and mixes the pure oxygen and compressed air to eliminate human error.

If there are any issues with the blend, there are a variety of display warnings as well as an audible alarm and a vibrating mouth piece to ensure a diver is aware of the situation. Because the dives are no-decompression recreational dives, a diver with an issue will simply need to flip the switch on their mouth piece to use the open-circuit and start a safe ascent.

This is part three of a four-part series on PADI’s new specialty diving certifications.

— Isaac Stone Simonelli


Get more from The Thaiger

Join the conversation and have your say on Thailand news published on The Thaiger.

Thaiger Talk is our new Thaiger Community where you can join the discussion on everything happening in Thailand right now.

Please note that articles are not posted to the forum instantly and can take up to 20 min before being visible. Click for more information and the Thaiger Talk Guidelines.

Archiving articles from the Phuket Gazette circa 1998 - 2017. View the Phuket Gazette online archive and Digital Gazette PDF Prints.

Follow Thaiger by email:

Thailand11 hours ago

Thailand News Today | Opposition to extending nightlife to 4am

Crime11 hours ago

Police officer who shot noodle vender sentenced to 25 years

Road deaths11 hours ago

Truck overturns in NE Thailand, driver dies, losing 1.5 million baht of beer

Sponsored2 days ago

British International School, Phuket: Reflecting on 25 years of world-class education

Transport11 hours ago

Thailand Transport Ministry seeks foreign loans for new bridges

Central Thailand12 hours ago

Elephant calf stamped to death in central Thailand

Chon Buri12 hours ago

Mountain B Pub’s real owner surrenders while police guard venue

Join the conversation on the Thaiger Talk forums today!
Road deaths12 hours ago

Motorcycle rider killed in multi-vehicle pile-up near Bangkok

Crime12 hours ago

Hong Kong man goes to Thailand to meet ‘lover,’ gets trafficked to Myanmar

Thailand13 hours ago

A monk dies in yet another day of Buddhist shame in Thailand

Economy13 hours ago

Electricity prices soar 18% to 4.72 baht per unit next month

Best of13 hours ago

Top 5 Boarding Schools in Thailand (2022)

Crime13 hours ago

Four national park officials indicted over Karen activist’s murder in western Thailand

Thailand14 hours ago

100 Consecutive Days of food handouts to the homeless of Bangkok

Protests14 hours ago

Nearly 1,000 locals protest over fatal road in central Thailand

Insurgency15 hours ago

Landmines kill 1, injure 10 in Deep South of Thailand

Thailand11 months ago

Morning Top Stories Thailand | Police to end protests, Human Trafficking | September 14

Thailand1 year ago

Thailand News Today | Thai Airways in rehab, All go for Songkran | March 4

Tourism1 year ago

Phuket’s nightlife. Yes, bars and clubs are still open | VIDEO

Phuket1 year ago

Thailand News Today | Covid passport talks, Thai Airways heads to court | March 2

Tourism1 year ago

Phuket Thai food treats you need to try | VIDEO

Thailand1 year ago

Thailand News Today | Bars, pubs and restaurants ‘sort of’ back to normal | Feb 23

Tourism1 year ago

In search of Cat & Dog Cafés in Phuket Town | VIDEO

Thailand2 years ago

Thailand News Today | Gambling crackdown, Seafood market to reopen, Vlogger challenge | Jan 21

Thailand2 years ago

Thailand News Today | Covid testing for visas, Business impact, Vaccine approval | January 19

Thailand2 years ago

Thailand News Today | Weekend Bangkok bombs, Thailand fires, Covid update | January 18

Thailand2 years ago

Thailand News Today | Stray car on runway, Indonesian quake, 300 baht tourist fee | January 15

Thailand2 years ago

Thailand News Today | Governor off respirator, sex-trafficking arrest, condo prices falling | January 14

Thailand2 years ago

Thailand News Today | Chinese vaccine, Thailand ‘drug hub’, Covid update | January 13

Thailand2 years ago

Thailand News Today | Bangkok may ease restrictions, Phuket bar curfew, Vaccine roll out | January 12

Thailand2 years ago

Thailand News Today | Covid latest, Cockfights closed down, Bryde’s Whale beached | January 11