Rebreather World - View Single Post - Article from COMEX Scientific Director on rebreathers, decompression and Penny Glover

SFM · 24th May 2006, 09:48

PMR: You mentioned for comparison sake the problems related to depth and duration for air dives. But today every diver has a decompression computer…
BG: Yes but those computers aren’t adapted to extreme dives. For 20 minutes at 60m, they may still be ok, after that the indications make no sense anymore. In those situations, haldanian models require very lengthy tissues that have not been integrated in computers and we meet again the physiological elimination limits we discussed earlier…

PMR: Back to rebreathers and trimix. Since they allow for deep dives, why not diffusing the validated tables which truly ensure divers’ security?
BG: It’s a matter of responsibility that didn’t likely exist 15 years ago. The root of the problem is the absence of control for their possible uses. A table is a marching order and does not condition the entire security of the dive. Diffusing tables officially is an official responsibility commitment. The Navy refuses to do so and COMEX, after hesitations, had to renounce as well. It’s possible to dive securely 40 minutes at 80m but it requires very consequent means that don’t fit leisure/hobby diving. Believing that a rebreather is the panacea, as stated in a show broadcasted on La Cinq (French TV channel), constitutes a crude mistake. That said and at a personal level, I’m willing to give the tables but I need to know the divers who will be using them, know their motivations, trust them. I have done it for a few, among them Pascal Barnabe in the framework of his record attempt. I warned him about the suicidal aspect of his endeavor but he was so determinated, he would have done it anyway. He’s an exceptional diver… So in those conditions let’s maximize his security…

PMR: Then you are opposed to trimix use in rebreathers?
BG: No, it’s the opposite. It’s an extraordinary tool for pros mention B, movie makers, biologists, archeologists who plan and organize their dives rigorously. But one has to keep in mind that the exceptional performances of rebreathers can turn against him/her. During dives the limit is Man, and amateurs shall limit themselves to short dives who don’t require excessive decompression times.

PMR: Divers can contact you then?
BG: Yes of course. A few months ago, FFESSM started a process in that direction. We wished for a study to be launched. We have Doppler bubble detectors, compact and very simple to use. Developped by Jean-Claude Dumas from Aqualab System, they cost only 1500 euros each. Their use on the ground (Translator: in the water that is…) would allow us to refine our work. With a study on ten divers, we know already perfectly if we’re at 1%, 0.1% or 0.01% risk level. In short, we know if it’s a risky dive or not. It would be a pertinent experience for trimix diving done by sporty divers and for which we lack data…

Contact: Bernard Gardette <comexsa at comex.fr>

24th May 2006, 09:48	#7 (permalink)
SFM New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: May 2006 Location: West Coast Posts: 11	Re: Article from COMEX Scientific Director on rebreathers, decompression and Penny Gl PMR: You mentioned for comparison sake the problems related to depth and duration for air dives. But today every diver has a decompression computer… BG: Yes but those computers aren’t adapted to extreme dives. For 20 minutes at 60m, they may still be ok, after that the indications make no sense anymore. In those situations, haldanian models require very lengthy tissues that have not been integrated in computers and we meet again the physiological elimination limits we discussed earlier… PMR: Back to rebreathers and trimix. Since they allow for deep dives, why not diffusing the validated tables which truly ensure divers’ security? BG: It’s a matter of responsibility that didn’t likely exist 15 years ago. The root of the problem is the absence of control for their possible uses. A table is a marching order and does not condition the entire security of the dive. Diffusing tables officially is an official responsibility commitment. The Navy refuses to do so and COMEX, after hesitations, had to renounce as well. It’s possible to dive securely 40 minutes at 80m but it requires very consequent means that don’t fit leisure/hobby diving. Believing that a rebreather is the panacea, as stated in a show broadcasted on La Cinq (French TV channel), constitutes a crude mistake. That said and at a personal level, I’m willing to give the tables but I need to know the divers who will be using them, know their motivations, trust them. I have done it for a few, among them Pascal Barnabe in the framework of his record attempt. I warned him about the suicidal aspect of his endeavor but he was so determinated, he would have done it anyway. He’s an exceptional diver… So in those conditions let’s maximize his security… PMR: Then you are opposed to trimix use in rebreathers? BG: No, it’s the opposite. It’s an extraordinary tool for pros mention B, movie makers, biologists, archeologists who plan and organize their dives rigorously. But one has to keep in mind that the exceptional performances of rebreathers can turn against him/her. During dives the limit is Man, and amateurs shall limit themselves to short dives who don’t require excessive decompression times. PMR: Divers can contact you then? BG: Yes of course. A few months ago, FFESSM started a process in that direction. We wished for a study to be launched. We have Doppler bubble detectors, compact and very simple to use. Developped by Jean-Claude Dumas from Aqualab System, they cost only 1500 euros each. Their use on the ground (Translator: in the water that is…) would allow us to refine our work. With a study on ten divers, we know already perfectly if we’re at 1%, 0.1% or 0.01% risk level. In short, we know if it’s a risky dive or not. It would be a pertinent experience for trimix diving done by sporty divers and for which we lack data… Contact: Bernard Gardette <comexsa at comex.fr> Last edited by SFM : 24th May 2006 at 10:17.
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