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**Gill Envy** · 25th April 2006, 21:52

jon, it seems that your question is both about rebreathers in general and also more specifically a comparison about the safety of the megaladon vs the inspiration. As a new rebreather diver (I apologize in advance if I come across as blindly faithful and over zealous), this is an area i have focused a great deal of energy on in choosing which unit to go with, though I am by no means an authority on the subject and in the end had to go with my gut. I have heard from a friend who has connection with inner space that there are about 300 megs out there, it sound like 280 is a more exact number. If my understanding is correct the inspo totals in the thousands and the evolution totals around 500 units. Trying to compare the safety of each based on the number of fatalities on each model is not necessarily a very good gage, but a natural thing to do none the less. I think it’s the pros that take the hits because they are the ones at the cutting edge of what has been done, they are the pioneers pushing the envelope. History is full of the discoveries of pioneers as well as their perilous and sometimes fatal adventures. I have to say that when we dropped in for a meeting at my old dive club here in seattle to get up to speed on the latest with re-breathers and they were holding a memorial for Zack, who died on a meg, (he used to give me air fills, at my dive shop!) it did not bode well for rebreathers in general or the meg in particular with my wife and I…it was only natural to take it as an omen of some sort. But I resisted this and in the end it was not enough on it’s own to steer me away from the meg. I think the number of increased fatalities on the meg likely has more to do with it’s rise in popularity with pretty hard core pioneering divers. It’s very hard to know in the end and this is a topic of much debate on this board that seems to boil down to speculation and opinion. I’m frustrated by the lack of solid evidence as to the actual causes of death, it makes me wonder if we are not all missing something that is staring us in the face. I have promised myself that with each death I will re-confirm my resolve to stay disciplined and stay on my toes with what I’ve been trained to observe and also to take another look to see if there is anything that I can do to improve my safety, in particular anything I can learn from the mistakes of others.
Without solid evidence about which unit is actually less likely to kill me under the conditions that I dive, I was won over by a few redundancies and safety mechanisms of the vision electronics on my evolution. Here is my case for why I think the vision electronics is the most reliable. (Keep in mind thought that I only have about 700 minutes on my rig and am just sharing my opinion, not trying to invalidate anyones different choice)
Unlike many meg divers who fly their rigs manually, I am of a different philosophy and like the idea of “auto pilot flying” unless conditions require otherwise and am thus very happy with the vision electronics. I think it's best to either go with a unit like the KISS that is completely manual, requiring constant monitoring or go with the model that has the most redundant automated system...and still pay constant attention to what it is doing.
The vision’s continuous injection system, built in deco, temp stick, redundant real time dual PO2 controlling systems, independent yet combinable battery systems and the sheer volume of vision electronics out there with very few deaths (only 2 that I know of) all convinced me that the vision electronics were the way to go as far as safety and convenience and yet I know that nothing can replace good common sense and staying alert.
The continuous injection system of the vision electronics is designed to inject oxygen continuously if the PO2 drops suddenly for any reason until the set point is regained not injecting just at set intervals. This system has the ability to respond rapidly, and it makes for a good argument that my chances of passing out from a sudden drop is less likely.
The temp stick, while not perfect is a major advancement in my opinion. Aside from likely preventing you from getting very far if you forgot to change out your scrubber, it gives a “real time” gage of how reactive your scrubber is. I think it’s fair to say it reduces risk of exhausting your scrubber, but again, no empirical stats to back it up and there are some conceivable scenarios where breakthrough could be possible even if the gage showed it were functioning normally.
We are confident that the trimix version (other versions have been buggy in the past) of the vision electronics makes either the evo or inspo the most reliable rebreather on the market today, at least for the kind of diving we do. And so far it SEEMS that it’s track record of low deaths supports this. I hope that helps. Safe diving, whichever model you choose!

25th April 2006, 21:52	#5 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,313	Re: Rebreather Safety: Megalodon vs. Inspiration jon, it seems that your question is both about rebreathers in general and also more specifically a comparison about the safety of the megaladon vs the inspiration. As a new rebreather diver (I apologize in advance if I come across as blindly faithful and over zealous), this is an area i have focused a great deal of energy on in choosing which unit to go with, though I am by no means an authority on the subject and in the end had to go with my gut. I have heard from a friend who has connection with inner space that there are about 300 megs out there, it sound like 280 is a more exact number. If my understanding is correct the inspo totals in the thousands and the evolution totals around 500 units. Trying to compare the safety of each based on the number of fatalities on each model is not necessarily a very good gage, but a natural thing to do none the less. I think it’s the pros that take the hits because they are the ones at the cutting edge of what has been done, they are the pioneers pushing the envelope. History is full of the discoveries of pioneers as well as their perilous and sometimes fatal adventures. I have to say that when we dropped in for a meeting at my old dive club here in seattle to get up to speed on the latest with re-breathers and they were holding a memorial for Zack, who died on a meg, (he used to give me air fills, at my dive shop!) it did not bode well for rebreathers in general or the meg in particular with my wife and I…it was only natural to take it as an omen of some sort. But I resisted this and in the end it was not enough on it’s own to steer me away from the meg. I think the number of increased fatalities on the meg likely has more to do with it’s rise in popularity with pretty hard core pioneering divers. It’s very hard to know in the end and this is a topic of much debate on this board that seems to boil down to speculation and opinion. I’m frustrated by the lack of solid evidence as to the actual causes of death, it makes me wonder if we are not all missing something that is staring us in the face. I have promised myself that with each death I will re-confirm my resolve to stay disciplined and stay on my toes with what I’ve been trained to observe and also to take another look to see if there is anything that I can do to improve my safety, in particular anything I can learn from the mistakes of others. Without solid evidence about which unit is actually less likely to kill me under the conditions that I dive, I was won over by a few redundancies and safety mechanisms of the vision electronics on my evolution. Here is my case for why I think the vision electronics is the most reliable. (Keep in mind thought that I only have about 700 minutes on my rig and am just sharing my opinion, not trying to invalidate anyones different choice) Unlike many meg divers who fly their rigs manually, I am of a different philosophy and like the idea of “auto pilot flying” unless conditions require otherwise and am thus very happy with the vision electronics. I think it's best to either go with a unit like the KISS that is completely manual, requiring constant monitoring or go with the model that has the most redundant automated system...and still pay constant attention to what it is doing. The vision’s continuous injection system, built in deco, temp stick, redundant real time dual PO2 controlling systems, independent yet combinable battery systems and the sheer volume of vision electronics out there with very few deaths (only 2 that I know of) all convinced me that the vision electronics were the way to go as far as safety and convenience and yet I know that nothing can replace good common sense and staying alert. The continuous injection system of the vision electronics is designed to inject oxygen continuously if the PO2 drops suddenly for any reason until the set point is regained not injecting just at set intervals. This system has the ability to respond rapidly, and it makes for a good argument that my chances of passing out from a sudden drop is less likely. The temp stick, while not perfect is a major advancement in my opinion. Aside from likely preventing you from getting very far if you forgot to change out your scrubber, it gives a “real time” gage of how reactive your scrubber is. I think it’s fair to say it reduces risk of exhausting your scrubber, but again, no empirical stats to back it up and there are some conceivable scenarios where breakthrough could be possible even if the gage showed it were functioning normally. We are confident that the trimix version (other versions have been buggy in the past) of the vision electronics makes either the evo or inspo the most reliable rebreather on the market today, at least for the kind of diving we do. And so far it SEEMS that it’s track record of low deaths supports this. I hope that helps. Safe diving, whichever model you choose! __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°> Last edited by Gill Envy : 25th April 2006 at 22:02.
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