Rate of PO2 drop changes with depth true/false

**UWSojourner** · 27th December 2006, 07:31

Quote: (Originally Posted by Genesis)

IMHO you're being far too charitable. Why?

Maybe it's a good thing to have found a better way of teaching/understanding RBs and move forward.

I didn't hear Joe saying the text was "right". He admitted it could be written better. That's good.

Seems like Sutty got the attention of those who might be able to correct it (at least 1 text). That's a reason to be hopeful, not a reason to assemble a firing squad.

***jradomski*** · 27th December 2006, 07:38

Quote: (Originally Posted by Genesis)

The manual in question is referring to a CCR, not a SCR, and clearly, they do not intend to say that you would have a 7.0 PO2 at that depth. That would cause instant death - nobody is going to parse it that way.

IMHO all who own this book now need to be tracked down and notified, and a "paste over" page, along with a written explanation and apology, need to go out. For those books not yet sold, they should either be fixed with said "paste over" or destroyed and the volume reprinted.

IANTD and the instructors today can (successfully) hide behind their waivers if an accident were to be traced to this. Now perhaps it becomes a bit more clear why I believe that the sort of fix that I put forward in the thread at http://www.rebreatherworld.com/rebre...del-liability-
law.html needs to be enacted. While that specific version of the model law would not hold IANTD responsible for an error such as this, the framework would provide a way to do so - so clearly, what's there needs some editing done on the model statute....

The IANTD book is about CCRs, not SCRs, and makes no statement implying that a constant-fIO2 unit is under discussion. Indeed, it is absolutely clear (from their talk about a setpoint of 0.7 and the solenoid cadence!) that they are discussing eCCRs in this section of the text.

IMHO you're being far too charitable. Why?

CCR manuals need to discuss SCR topics since for many types of dives this is the best way to get your ass out of trouble by running the CCR as a manual SCR.. Without reading the text in question I can't comment on the train of thought.. I have to give the benefit of doubt towards the author since the intent may have been there but poorly worded causing confusion..
If the INTENT was to say that the actual po2 drop was slower at depth then it's clearly wrong, if the INTENT was that the loop in certain uses can be used longer at depth than at the surface then its correct in that aspect even though the wording may lead to other and wrong conclusions.

**nigelh** · 27th December 2006, 08:34

Quote: (Originally Posted by Genesis)

You will find that the waiver you signed when you take a class, dive somewhere, or do anything else diving-related in this state really does go so far as to release everyone involved even if they pump your tank full of carbon monoxide or is drunk while they're teaching you - despite the fact that there are lots of people out there who will proclaim that "oh you can't release negligence and you SURELY can't release gross negligence."

I fear in the USA you can sign away your 'rights'.

However in the UK we sign any disclaimer a dive shop puts in front of us and know they can't get away with much other than our money:

Quote:

Section 2(1) of the Unfair Contract Terms Act 1977 as amended which states:
2 Negligence liability
(1) A person cannot by reference to any contract term or to a notice given to persons generally or to particular persons exclude or restrict his liability for death or personal injury resulting from negligence.

However I doubt anybody would take issue with text like this. It's just an error. It doesn't advocate any unsafe practises, any bad techniques or stupid skills it just warns you to beware of a problem that doesn't exist. It's like warning you against the danger of being trampled by pink elephants shore diving at Morangie on the Dornoch Firth. They may have been reported, probably adjacent to the distillery, but nobody has yet been trampled.

Sutty · 27th December 2006, 13:19

I'd like to point out that I have not been trying to berate IANTD or any other training agency. I suspect the misconception extends beyond a single agency in any case. I do think this error is worth correcting, however the belief that you have a bigger safety margin at depth (except by virtue of a higher PO2), is only a problem if you allow yourself to become complacent in the first place. In my opinion it is always the responsibility of the diver to keep good control/monitoring of their PO2.
Trying to contact every owner of a particular manual would be an excessive and ineffective response - it is unlikely to reach everyone in the real world anyway.
I do feel it would be appropriate for IANTD to correct the error in the next printing, and amend the errata which are sent out as a loose sheet with the manual for new recipients. Other than that just sending a message to their instructor network to ensure thay are not promulgating the error should be enough.

Neil

P.S. Please don't turn this thread into a shouting match about legal requirements and responsibilities as this will only dilute the message for future readers. Start a new thread if you feel it is required.

cramerdn · 27th December 2006, 14:08

Quote: (Originally Posted by Sutty)

I do feel it would be appropriate for IANTD to correct the error in the next printing, .

Next printing? What is that 5 or 6 years for IANTD?

Genesis · 27th December 2006, 14:53

Well, I think the book needs to be recalled, and those who were taught under it need to be notified.

This isn't about legal requirements - its about doing what's right. The comment that this is "ivory tower" is, IMHO, way, way out of line.

This is simply not that expensive to fix. A 39 cent stamp and a couple of pages of paper will do for everyone in the US. IANTD certainly knows who they certified using this text, right?

But - let's say it was expensive to fix. So what? Shouldn't we expect that errors that can put people's lives at risk be fixed when found? Is it "kosher" to deliver units for years with "battery bounce" problems even after you know about them and then, later on, only "fix" them when someone sends the unit in for a $1,000 service call? Is it ok to accept a battery cap design that has contact problems and leads to resets and involuntary injection under water?

What I don't get is why anyone would not expect an immediate corrective response when a safety-related item like this comes to light!

Dutchy · 27th December 2006, 15:38

Quote: (Originally Posted by Genesis)

Well, I think the book needs to be recalled, and those who were taught under it need to be notified.

Oops that book can be ordered from bookstores as well. Only the ones taught using this book need to be informed? From a practical point of view it's not possible.

The next question would be how dangerous is it? If it is really life threatening then the only right thing is to announce it to the press and put adds in papers.

But is it? I've been taught that at depth I probably need not inject oxygen as often as on the surface. But would I rely on that? I've also been taught not to CCR dive blind (that is without trustworthy pPO2 indication). In case of doubt bail-out. I've also been told
to use a 5:1 SCR ratio when the remedy is to go SCR. If I willingly break that rule only because I read something reassuring then what ratio would I use at dept? Do I need to pick an arbitrary number because there's allegedly some room for that? I don't need you to answer that question my only point is to make clear that this statement doesn't come on it's own. CCR divin is governed by a series of rules this one is low on the priority list. If you die because you think there's extra safety in this then you've made a series of other capital mistakes.

Genesis · 27th December 2006, 15:57

You're right - you can't reach everyone. Just like you can't reach everyone with a consumer product, and posting notices doesn't (really) reach everybody either.

But IANTD does know who was certified by them using this book (in whole or part) as textbook material. Those people can and should be contacted.

27th December 2006, 07:31	#51 (permalink)
UWSojourner Pacific Northwest Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Location: Portland Oregon Posts: 556	Re: Rate of PO2 drop changes with depth true/false Quote: (Originally Posted by Genesis) IMHO you're being far too charitable. Why? Maybe it's a good thing to have found a better way of teaching/understanding RBs and move forward. I didn't hear Joe saying the text was "right". He admitted it could be written better. That's good. Seems like Sutty got the attention of those who might be able to correct it (at least 1 text). That's a reason to be hopeful, not a reason to assemble a firing squad.
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27th December 2006, 07:38	#52 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 2,885	Re: Rate of PO2 drop changes with depth true/false Quote: (Originally Posted by Genesis) The manual in question is referring to a CCR, not a SCR, and clearly, they do not intend to say that you would have a 7.0 PO2 at that depth. That would cause instant death - nobody is going to parse it that way. IMHO all who own this book now need to be tracked down and notified, and a "paste over" page, along with a written explanation and apology, need to go out. For those books not yet sold, they should either be fixed with said "paste over" or destroyed and the volume reprinted. IANTD and the instructors today can (successfully) hide behind their waivers if an accident were to be traced to this. Now perhaps it becomes a bit more clear why I believe that the sort of fix that I put forward in the thread at http://www.rebreatherworld.com/rebre...del-liability- law.html needs to be enacted. While that specific version of the model law would not hold IANTD responsible for an error such as this, the framework would provide a way to do so - so clearly, what's there needs some editing done on the model statute.... The IANTD book is about CCRs, not SCRs, and makes no statement implying that a constant-fIO2 unit is under discussion. Indeed, it is absolutely clear (from their talk about a setpoint of 0.7 and the solenoid cadence!) that they are discussing eCCRs in this section of the text. IMHO you're being far too charitable. Why? CCR manuals need to discuss SCR topics since for many types of dives this is the best way to get your ass out of trouble by running the CCR as a manual SCR.. Without reading the text in question I can't comment on the train of thought.. I have to give the benefit of doubt towards the author since the intent may have been there but poorly worded causing confusion.. If the INTENT was to say that the actual po2 drop was slower at depth then it's clearly wrong, if the INTENT was that the loop in certain uses can be used longer at depth than at the surface then its correct in that aspect even though the wording may lead to other and wrong conclusions. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated. Last edited by jradomski : 27th December 2006 at 07:44.
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27th December 2006, 08:34	#53 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 824	Re: Rate of PO2 drop changes with depth true/false Quote: (Originally Posted by Genesis) You will find that the waiver you signed when you take a class, dive somewhere, or do anything else diving-related in this state really does go so far as to release everyone involved even if they pump your tank full of carbon monoxide or is drunk while they're teaching you - despite the fact that there are lots of people out there who will proclaim that "oh you can't release negligence and you SURELY can't release gross negligence." I fear in the USA you can sign away your 'rights'. However in the UK we sign any disclaimer a dive shop puts in front of us and know they can't get away with much other than our money: Quote: Section 2(1) of the Unfair Contract Terms Act 1977 as amended which states: 2 Negligence liability (1) A person cannot by reference to any contract term or to a notice given to persons generally or to particular persons exclude or restrict his liability for death or personal injury resulting from negligence. However I doubt anybody would take issue with text like this. It's just an error. It doesn't advocate any unsafe practises, any bad techniques or stupid skills it just warns you to beware of a problem that doesn't exist. It's like warning you against the danger of being trampled by pink elephants shore diving at Morangie on the Dornoch Firth. They may have been reported, probably adjacent to the distillery, but nobody has yet been trampled. __________________ nigelh
(Online)

27th December 2006, 13:19	#54 (permalink)
Sutty Classic Kiss diver Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Jun 2005 Location: Glossop, Derbyshire, UK Posts: 784	Re: Rate of PO2 drop changes with depth true/false I'd like to point out that I have not been trying to berate IANTD or any other training agency. I suspect the misconception extends beyond a single agency in any case. I do think this error is worth correcting, however the belief that you have a bigger safety margin at depth (except by virtue of a higher PO2), is only a problem if you allow yourself to become complacent in the first place. In my opinion it is always the responsibility of the diver to keep good control/monitoring of their PO2. Trying to contact every owner of a particular manual would be an excessive and ineffective response - it is unlikely to reach everyone in the real world anyway. I do feel it would be appropriate for IANTD to correct the error in the next printing, and amend the errata which are sent out as a loose sheet with the manual for new recipients. Other than that just sending a message to their instructor network to ensure thay are not promulgating the error should be enough. Neil P.S. Please don't turn this thread into a shouting match about legal requirements and responsibilities as this will only dilute the message for future readers. Start a new thread if you feel it is required. __________________ Never forget that life is a finite resource.
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27th December 2006, 14:08	#55 (permalink)
cramerdn Obey my dog! Current Rebreather/s: Evolution Dolphin Other Rebreather/s: Dolphin Join Date: Dec 2006 Location: Townsville QLD Posts: 534	Re: Rate of PO2 drop changes with depth true/false Quote: (Originally Posted by Sutty) I do feel it would be appropriate for IANTD to correct the error in the next printing, . Next printing? What is that 5 or 6 years for IANTD?
(Online)

27th December 2006, 14:53	#56 (permalink)
Genesis Bubbless Box of Death Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Oct 2005 Location: Sunny Florida Posts: 1,394	Re: Rate of PO2 drop changes with depth true/false Well, I think the book needs to be recalled, and those who were taught under it need to be notified. This isn't about legal requirements - its about doing what's right. The comment that this is "ivory tower" is, IMHO, way, way out of line. This is simply not that expensive to fix. A 39 cent stamp and a couple of pages of paper will do for everyone in the US. IANTD certainly knows who they certified using this text, right? But - let's say it was expensive to fix. So what? Shouldn't we expect that errors that can put people's lives at risk be fixed when found? Is it "kosher" to deliver units for years with "battery bounce" problems even after you know about them and then, later on, only "fix" them when someone sends the unit in for a $1,000 service call? Is it ok to accept a battery cap design that has contact problems and leads to resets and involuntary injection under water? What I don't get is why anyone would not expect an immediate corrective response when a safety-related item like this comes to light! __________________ "A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American." http://www.denninger.net http://www.diversunion.org/liability.htm - Fix the Diving Cert racket
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27th December 2006, 15:38	#57 (permalink)
Dutchy SK#007 Current Rebreather/s: Sport Kiss Other Rebreather/s: Join Date: Apr 2006 Location: Nieuwegein (The Netherlands) Posts: 729	Re: Rate of PO2 drop changes with depth true/false Quote: (Originally Posted by Genesis) Well, I think the book needs to be recalled, and those who were taught under it need to be notified. Oops that book can be ordered from bookstores as well. Only the ones taught using this book need to be informed? From a practical point of view it's not possible. The next question would be how dangerous is it? If it is really life threatening then the only right thing is to announce it to the press and put adds in papers. But is it? I've been taught that at depth I probably need not inject oxygen as often as on the surface. But would I rely on that? I've also been taught not to CCR dive blind (that is without trustworthy pPO2 indication). In case of doubt bail-out. I've also been told to use a 5:1 SCR ratio when the remedy is to go SCR. If I willingly break that rule only because I read something reassuring then what ratio would I use at dept? Do I need to pick an arbitrary number because there's allegedly some room for that? I don't need you to answer that question my only point is to make clear that this statement doesn't come on it's own. CCR divin is governed by a series of rules this one is low on the priority list. If you die because you think there's extra safety in this then you've made a series of other capital mistakes. __________________ = This post is environmentally friendly. It is composed of 100% recycled electrons only. = SK #007
(Online)

27th December 2006, 15:57	#58 (permalink)
Genesis Bubbless Box of Death Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Oct 2005 Location: Sunny Florida Posts: 1,394	Re: Rate of PO2 drop changes with depth true/false You're right - you can't reach everyone. Just like you can't reach everyone with a consumer product, and posting notices doesn't (really) reach everybody either. But IANTD does know who was certified by them using this book (in whole or part) as textbook material. Those people can and should be contacted. __________________ "A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American." http://www.denninger.net http://www.diversunion.org/liability.htm - Fix the Diving Cert racket
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