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I can't believe I'm doing this, but I am a person obsessed with attention to detail, so here goes: Steve Schultz wrote: <snip> I don't think that the problem is with recreational nitrox. I think that the problem is the way that it is taught by the agencies. <snip> I agree that the problem is the way it is taught, and that a good instructor can make a bad program better. Mr Thomas Tukker's post about this holds true. <snip> I proudly hide my tdi nitrox shingle and hope no one ever asks to see it. When I took the course, they said: -always use a bottom p02 of 1.6 except on unusually cold or strenuous dives (then use 1.4) -in this area all dives are cold with current and you are used to it so there is no problem always diving p02 of 1.6 <snip> This is the part where my neck goes on the block. I too, have a TDI Nitrox shingle. The TDI Nitrox book says (I'm paraphrasing here) that originally the USN (1963) and then NOAA (1990) reccomended the max PO2 of 1.6 for 45 minutes. TDI is referenceing the USN and NOAA for this MAXIMUM value. The BOOK goes on to say (again paraphrasing) that 1.4 should be used for cold/strenuous dives. This is the part where the good instructor comes in. MY TDI instructor told me that it was his opinion that 1.6 should never be used. He and I had a long discussion about this and I used my drift-diving-in-Florida example (sound familiar Jim Cobb?). My instructor went on to explain the issues about O2 tox, and basically told me it was better to be safe than dead. He said he personally uses 1.4 as a max. I think Mr. Steven Schultz's issues were with the instructor teaching something contrary to what was in the course text. I my opinion, that makes it the instructor's fault issue and not TDI's. I realize that TDI may not be teaching the correct information in some courses. However, it appears in this case that TDI has referenced some known organizations for this material. I am only trying to clarify between what is a bad instructor's teaching and what is the curriculum of the course, written in black and white. Like someone else said...I will now step off the soapbox and put on my flame retardant suit... Chris Brown Suffolk VA --- "Schultz, Steven" <Steven.Schultz@sp*.gc*.ca*> wrote: > Jim, > > I don't think that the problem is with recreational > nitrox. I think that > the problem is the way that it is taught by the > agencies. I proudly hide my > tdi nitrox shingle and hope no one ever asks to see > it. > > When I took the course, they said: > -always use a bottom p02 of 1.6 except on unusually > cold or strenuous dives > (then use 1.4) > -in this area all dives are cold with current and > you are used to it, so > there is no problem always diving p02 of 1.6 > > This is too stupid. I didn't realize that at the > time (I was 17 yrs old). > That was only a couple problems with the course. > They also encouraged > carrying a bottle of ean39 beyond its MOD for use as > a bailout gas. Where > have we heard this crap before??? > > Nitrox shouldn't be used to avoid a few minutes of > deco, but can be used to > increase safety. A lot of people diving at altitude > dive ean as air to > increase safety on recreational dives. > > The problem isn't with an 80 full of nitrox... The > problem is how the > industry teaches its use. > > ss > > -----Original Message----- > From: Jim Cobb [mailto:cobber@ci*.co*] > Sent: October 10, 2000 10:13 PM > To: klind@al*.ne*; dmdalton > Cc: dwiden@ho*.co*; donburke56@ne*.ne*; 'Paul > Braunbehrens'; > techdiver@aquanaut.com > Subject: Re: rec trimix > > > Kent- > > I guess I was a little obscure. What I am saying is > the nitrox presumption > that you can avoid deco for certain profiles by > cranking up your PP02 to 1.5 > or even 1.6. > > So I would not agree with the diver who does your > hypothetical dive who, > instead of using air and getting out of the water at > 20 mins, mixes a 40 > nitrox to stay in for 40 mins. Personally I would > prefer do 5 mins of deco > on 02. This limits your overall exposure to to the > high PP02's from 40 mins > at 1.44 to 5 mins at 1.6 while at rest. In tech > diving reserving your high > PP02 for deco gives you the opportunity to do air > breaks and give your lungs > a rest, something you can't do at the bottom. > > Jim > > ------------------------------------------------------------------- > Learn About Trimix at > http://www.cisatlantic.com/trimix/ > > > From: "Kent Lind" <klind@al*.ne*> > > Reply-To: <klind@al*.ne*> > > Date: Tue, 10 Oct 2000 16:37:53 -0800 > > To: <cobber@ci*.co*>, "dmdalton" > <dmdalton@qu*.ne*> > > Cc: <dwiden@ho*.co*>, <donburke56@ne*.ne*>, > "'Paul Braunbehrens'" > > <Bakalite@ba*.co*>, <techdiver@aquanaut.com> > > Subject: RE: rec trimix > > > > Jim: > > > > Maybe I'm missing the point of your post. But I > do what you describe all > > the time. Not the working PP02 over 1.2 but using > nitrox to reduce or > > eliminate deco time. > > > > Here's a hypothetical. What gas would you use for > say a 1 hour cave dive > at > > 85' max depth? That's a pretty typical profile. > Are you going to use > air, > > trimix, or something simple like nitrox 32 which > you can get pumped out of > > banks at the local shop? > > > > > > -----Original Message----- > > From: Jim Cobb [mailto:cobber@ci*.co*] > > Sent: Monday, October 09, 2000 10:55 AM > > To: dmdalton > > Cc: dwiden@ho*.co*; donburke56@ne*.ne*; 'Paul > Braunbehrens'; > > techdiver@aquanaut.com > > Subject: Re: rec trimix > > > > > > I know this is going to piss off a lot of rec > divers but I believe that > > increasing your bottom PP02's for the purpose of > avoiding a deco > obligation > > is a really stupid idea. It is typical of our > sport that this principle is > > embraced by almost everybody. Even to the point of > calling potentially > > deadly hyperoxic mixes "safeair". > > > > I think there should be an industry-wide ban of > bottom or working PP02's > of > > anything over 1.2. And if you need to spend more > time down there then you > > need to do it right with doubles and a deco plan. > The idea of "standard" > > trimixes with 02 of 32 or 36 or greater is inverse > to common sense. > > > > Jim > > > > On Monday, October 9, 2000, at 01:20 AM, dmdalton > wrote: > > > > David, Don & whomever else, > > > > Why does this need to be a gas that "tracks" air? > Anyone who would be > > interested in the minimal extra training necessary > for a recreationally > > oriented Trimix would either already be Nitrox > trained or certainly > capable > > of it. As was already pointed out a Tri-Ox course > could easily make Nitrox > a > > thing of the past. If we are talking about "no > stop dives" then wouldn't > it > > make sense to boost the O2 level to get some > increased bottom time? A > 21X24 > > @ 130 ft for 5 minutes calls for 1 min at 30, 20 & > 10 (Deco Planner GF - > lo > > 25/hi 90). While a 28 X 35 gives you 10 min @ 130 > and only adds 1 min at > 40 > > ft to the above. Nitrox has it's limits and so > would Tri-Ox. I would > venture > > to say that an individual breathing Tri-Ox of 28 X > 35 would be far less > > likely to ignore the 130 ft limit than someone > breathing EAN 28. > > > > As for the Rec Agencies, I think they will be the > ones to embrace this mix > > which would be one more specialty that they could > get into their > curriculum. > > They certainly have all embraced devil gas, I'm > sorry, Nitrox. Yeah, I > know > > it took a while but when Tri-Ox hit's for real > they will all jump on it > like > > a chicken on a June bug. The gentleman I took > Nitrox from ( a former NOAA > > Nitrox Diver of 14 years) was talking about > standardized Tri-Ox 32 & > Tri-Ox > > 36, 3 years ago when I took the course. > > > > I believe the bigger challenge is the few shops > that pump Trimix. In the > DC > > area I know of only one shop that pumps it and I > understand that they are > > getting in the neighborhood of $80 for a single > tank of Trimix. > Outlandish, > > but then I understand that in NY you can get hit > up $20 for a single of > > Nitrox. > === message truncated === __________________________________________________ Do You Yahoo!? Yahoo! Messenger - Talk while you surf! It's FREE. http://im.yahoo.com/ -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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