David,

Sorry. I moved the conversation away from the "drop in gas" idea which you
were responding to.

I  agree completely that it has to be very simple for it to be marketable by
the Rec Agencies and therefore accepted by the masses as THE breathing mix
for anything past a given depth (80 ft?).

As to costs, I actually think there would be very little cost to the Rec
Agencies in using TriOx in place of Nitrox. Tables have to be developed for
sure, but given the availability of the software, that would not be a large
cost and a basic nitrox computer design could be programmed to handle set
TriOx gas mixes like they are for set Nitrox mixes - no gas switches, just
select your O2 level with a standard HE amount of 30 or 35%. This would make
the manufacturers happy as they would have a new toy to sell.

One good thing about the high cost of HE fills in DC, it convinces one real
quickly to go do-it-yourself. My son and I last Friday burned enough 28/30
at DC prices (two sets of doubles) to cover the cost of my tank lease for
the year and the first three cylinders. On Wednesday we will cover the cost
of my whip :).

Dave Dalton

----- Original Message -----
From: David B. Widen <dwiden@ho*.co*>
To: 'dmdalton' <dmdalton@qu*.ne*>; <donburke56@ne*.ne*>; 'Paul
Braunbehrens' <Bakalite@ba*.co*>; <techdiver@aquanaut.com>
Sent: Monday, October 09, 2000 7:51 AM
Subject: RE: rec trimix


> The initial point of this was "a drop in replacvement gas".
>
> If this is going to be address to the recreational community which by
> definition is No Planned Decompression and doppler NDL tables. We need to
> look at it from the their point view and wallet.
>
> It is going to take a lot of education for the community. One still hears
> "Nitrox, isn't that a deep gas?". What are they going to say able Trimix?
>
> If you want an air drop in replacement, then use FO2 of .21 and reduce the
> narcotic affects with HE. Now if you want a Nitrox drop in then use those
> numbers.
>
> The next big question is "Will all this track on the Air and Nitrox
tables?"
> What happens to SIT and repetitive dives. The time I spend yesterday
w/Deco
> Planner (v2.0.49) and cooking up some plans (1st dive only). It appeared
to
> track well against SSI NDL tables.
>
> You cannot just look at this a technical diver cooking up a mix for your
> next dive. It must be looked at from the point idiot proofing and by the
> numbers. Or else it won't play at the dive centers and become readily
> available. What I hear about DC, they typically do not want to pump O2 for
> deco and say "oh my God you want HE -- not here".
>
> Then what happens to the old supply and demand question with HE and the
gas
> suppliers. There is a finite supply of HE in the world (sounds like crude
> oil).
>
> So what is the perfect mix for a recreation diver and fits into the NDL
> tables?
> So warm up those computers and start the spreadsheets and deco planners.
> Let's start cooking tables.
>
> David
>
> > -----Original Message-----
> > From: dmdalton [mailto:dmdalton@qu*.ne*]
> > Sent: Monday, October 09, 2000 1:21 AM
> > To: Widen, David B.; donburke56@ne*.ne*; 'Paul Braunbehrens';
> > techdiver@aquanaut.com
> > Subject: Re: rec trimix
> >
> >
> > 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.
> >
> > Dave Dalton
> >
> >
> > ----- Original Message -----
> > From: David B. Widen <dwiden@ho*.co*>
> > To: <donburke56@ne*.ne*>; 'Paul Braunbehrens'
> > <Bakalite@ba*.co*>;
> > <techdiver@aquanaut.com>
> > Sent: Sunday, October 08, 2000 2:53 PM
> > Subject: RE: rec trimix
> >
> >
> > > Don
> > >
> > > Good thought. It will be hell to get the rec agency to support.
> > > I ran some of the numbers through Deco Planner and some other
> > calculations.
> > >
> > > To more closely track air and without penalties a 21x24
> > works with END of
> > 80
> > > IAW DecoPlanner and END of 90 if you calc with N2 & O2 as
> > narcotic gases.
> > > Without building the whole tables w/SIT and repet groups. There are
> > several
> > > general mixes that would work well. The Normoxic value
> > would serve the
> > > uninformed or hard headed person who exceeds 130. It would
> > also support
> > and
> > > assist in the transistion of new divers to this type of
> > dive gas and idea.
> > >
> > > Type Cost: 21x24 $.215/cuft  21x30 $.252/cuft
> > > AL80 21x24 ~$17   21x30 ~$20
> > > ST95 21x24 ~$21   21x30 ~$24
> > >
> > > Cost increase 3 to 5 times without over fills.
> > >
> > > David
> > >
> > > > -----Original Message-----
> > > > From: Don Burke [mailto:donburke56@ya*.co*]
> > > > Sent: Sunday, October 08, 2000 7:56 AM
> > > > To: Paul Braunbehrens; techdiver@aquanaut.com
> > > > Subject: Re:rec trimix
> > > >
> > > >
> > > > Comments scattered within
> > > >
> > > > --- Paul Braunbehrens <Bakalite@ba*.co*> wrote:
> > > > > I think that this is where trimix computers come in.
> > > > >  Even if it's a
> > > > > good "drop in" gas, I'd still like to track what I'm
> > > > > really using.
> > > >
> > > > Certainly.  It isn't rocket science in any case.  I
> > > > haven't worked out _every_ possibility so the He
> > > > content may have to be backed off a couple of points
> > > > to stay inside the air tables.
> > > >
> > > > A set of rec-tri tables wouldn't seem to be too hard
> > > > to make up for repetitive diving, although PADI would
> > > > probably have to actually come up with a new set of
> > > > surface interval numbers to allow for He instead of
> > > > the Xerox solution used for the surface intervals on
> > > > the PADI EAN tables.
> > > >
> > > >
> > > > > Also, because of O2 Tox there would have to be some
> > > > > kind of an
> > > > > "orientation class" at the least.  If you go down to
> > > > > 160 on air and
> > > > > come back up right away you're stupid, but you won't
> > > > > tox on O2.  A
> > > > > "drop in" gas would need some serious warning if it
> > > > > has a higher O2
> > > > > content.
> > > >
> > > > Yeah, the orientation would be:
> > > >
> > > > "Remember when I told you to stay shallower than 130?
> > > > Well this time I mean it."
> > > >
> > > > You didn't mention the CNS clock, but since we are on
> > > > the subject of O2, I haven't figured out a way to run
> > > > out the clock with 28% O2 without going well into deco
> > > > stop diving or going below 130.  I doubt there is one.
> > > >
> > > > > Don Burke wrote:
> > > > > ~
> > > > > >As variation on the same theme, how about 28/35 as
> > > > > a "drop-in" replacement for air?
> > > > > >
> > > > > >It is good to 130 feet under any conditions a rec
> > > > > diver will see.
> > > > > >
> > > > > >The no stop times are longer than for air.
> > > > > >
> > > > > >The END at 130 feet is about 80 feet.
> > > > > >
> > > > > >The only downside is cost.
> > > > > >
> > > > > >Don Burke
> > > > > >Chesapeake, Virginia
> > > > > >
> > >
> > > --
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> > >
> >
>
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