Auckland Based Diver? Take Part In A CO2 Prebreathe Study This July

News, Rebreathers

Are you an Auckland based diver, or live near Auckland, New Zealand? Are you available on Saturday 19th or Sunday 20th July 2014? Do you dive a rebreather or are thinking of becoming a rebreather diver? If you answer ‘yes’ to these questions, Dr Simon Mitchell and Dr Neal Pollock need your help. They are conducting a Carbon Dioxide (CO2) Prebreathe Study and need volunteers to assist in this incredibly useful research.

We are delighted to report that the findings from this study will be announced at EUROTEK.2014 in September.

What is the purpose of this research?

Rebreathers which recycle exhaled gas after removing carbon dioxide (CO2) are becoming increasingly popular in recreational diving because they offer advantages such as the conservation of breathing gas. However, they are more complex than normal scuba equipment, and there is potential for operator error in their use. These errors may lead to accidents and death. Several of these potential operator errors relate to the use of the CO2 absorbent (or the CO2 “scrubber”). If there is failure of CO2 removal from the expired breath, the diver will re-inhale CO2 and this may result in hypercapnia (commonly referred to as CO2 toxicity). Rebreather divers are taught about this during their rebreather dive training. CO2 toxicity may cause progressive shortness of breath, headache, anxiety, panic, and ultimately unconsciousness. In addition, CO2 toxicity enhances the adverse effects or toxicity of other gases such as nitrogen and oxygen. There have been many deaths during the use of rebreathers in which CO2 toxicity is thought to have contributed, though this is often difficult to prove.

The absorbent material used in CO2 scrubbers must be replaced periodically. Related errors include failing to replace the absorbent material, incorrect packing of the absorbent material into the scrubber canister, and incorrect installation of the canister in the rebreather (or forgetting to install it entirely). Most rebreather units do not monitor CO2, and so rebreather divers are taught to conduct a 5 minute “pre-breathe” of their unit just before entering the water. A prebreathe involves preparing the unit for diving, and then sitting quietly breathing on the rebreather loop. If the CO2 scrubber is absent or faulty the diver will rebreathe CO2 and, in theory, should notice the early symptoms of CO2 toxicity such as shortness of breath or headache.

Divers assume that symptoms of CO2 toxicity will occur reliably and be noted during a 5 minute prebreathe. However, this has never been formally tested. This study aims to measure the proportion of subjects who can identify the absence of an effective scrubber during a 5 minute prebreathe on a rebreather circuit. The detection of a partial scrubber failure may also be evaluated.

If you want to be part of this important study please email PADI Course Director Pete Mesley as soon as possible to get booked in. You will be needed for no more than 2 hours during the course of the weekend.

Dr Simon Mitchell and Dr Neal Pollock will be presenting their research at EUROTEK 2014

Dr Simon Mitchell and Dr Neal Pollock will be presenting their research at EUROTEK.2014


Photo Credit: Jason Brown / BARDOPhotographic


Not just for guys….

Events, News, Rebreathers

Once more Innerspace was hosted by PADI resort, Divetech in Grand Cayman and with Nancy Easterbrook leading the team it’s no wonder that the event attracts both sexes to dive in the beautiful blue waters. And just to prove that rebreather diving is just as popular with us girls here is this year’s line up including PADI Rebreather IT,  Georgia Hausserman

Ladies at Innerspace

Thanks to Jay Easterbrook and Divetech for the photo.

Join PADI at TEKcamp 2014

Events, News, Rebreathers, Sidemount, Tec Rec

Join me for this amazing week of workshops where you will have the chance to improve and fine tune your tec diving skills as well as experience new equipment and hear talks from top Training Directors and Explorers. There will be loads of manufacturers, such as fourth element,  with lots of lovely equipment for you to try out and plenty of opportunities to pose for photos, with Sport Diver in attendance, not to mention the fantastic atmosphere that comes from spending a week with experts and enthusiasts alike. All hosted by PADI Dive Centre, Vobster Quay, whose legendary hospitality is never more evident than at TEKcamp.

Visit to book your place or email me: if you have any questions and I’ll be happy to pass them on.

Visit to book your place!

Visit to book your place!




Is the future of diving robotic?

News, Technology

No we’re not talking about staying at home and diving in a virtual world, where you never get wet!

Here at PADI we always have our ears to the ground. As well as monitoring research and developments in recreational and technical diving we also love to hear about other areas of diving. CADDY is an interesting research project being carried out by the scientific and commercial diving communities.


The launch of the CADDY research program

The launch of the CADDY research program

CADDY is a project to develop a sophisticated robot buddy to assist divers working underwater.

This raises some interesting questions for the future of diver training.

How could this kind of technology be used to improve diver safety during training dives?

What features would be needed on a similar tool for recreational divers and/or instructors?

We’d love to hear your comments.


Rebreather Training Council is formed


On May 18, the first face-to-face meeting of the newly formed Rebreather Training Council (RTC) took place in Miami, USA during the inaugural TEKDiveUSA 2014 conference.

The members of the RTC are training organisations that offer courses in the use of rebreathers. The RTC aims to promote safety and standardisation in the field of rebreather training, and the group intends to work closely with the Rebreather Education and Safety Association (RESA) to achieve these goals.

The members of the RTC are: American Nitrox Divers Inc. (ANDI), Global Underwater Explorers (GUE), International Association of Nitrox and Technical Divers (IANTD), International Association of Rebreather Trainers (IART), National Association of Underwater Instructors (NAUI), Professional Association of Diving Instructors (PADI), Professional Scuba Association International (PSAI), RAID, Scuba Schools International (SSI) and Technical Diving International (TDI).