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tom,as usual,this is some of the stupidest stuff i have ever heard.
On Thu, 14 May 1998, Tom Mount wrote:
> Bill
> I would like to take a moment to clarify a couple of issues with you on
> IANTD=92s recommendation of the use of EAN 80 in TRAINING PROGRAMS. I wil=
l not
> go into detailed history on how we evolved to the use of EAN 80 as I have
> already explained that.
>=20
> When you did your training we were (if I remember correctly) still using
> oxygen on deco.
>=20
> Over time I witnessed as did other instructors some (only a few, but stil=
l
> important to safety) divers develop oxygen toxicity symptoms on oxygen at
> the 20 foot stop. This included one diver who like all of us had been usi=
ng
> oxygen for several years as a deco gas.
so he's now dead?the main symptom that you would notice in one of your
students develoiping oxygen "toxity" would be
convulsions.now,please,mr.wizard,explain to me how breathing a gas with a
ppo2 of 1.6 at 30' (such as 80/20) is better then breathing a gas with a
ppo2 of 1.6 at 20' (such as 100% oxygen)???
> Based on the point that a few people had exhibited in water symptoms we f=
elt
> it was not a good policy to REQUIRE the use of oxygen at 20 feet (1.6PO2)=
So
> the big issue for us in training in regard to oxygen decompression is the
> 20-foot stop exposure.
so you decide not to require oxygen at 20',instead now you prohibit it
and require the use of 80/20 (1.6PO2 as you say) at 30 feet.what is the
difference between 1.6ppo2 at 30' and 1.6ppo2 at 20'?with your many years o=
f
diving experience,and your obvious understanding of mathmatics,physics,and
diving physiology,you should be able to explain something as simple as this
to us.the reality is there is no difference between 1.6ppo2 at 30' and 20'.
>=20
> Then of course there is the additional problem in open sea (caves have mo=
re
> stability and fresh water a slightly lower PO2) decompression as divers t=
end
> to vary a couple of feet even with good buoyancy control due to changes i=
n
> body attitude, waves passing overhead, or when on down lines not being ab=
le
> to get to the exact 20 foot stop even with the use of John lines in curre=
nt
> (every one does not have the freedom of being able to hang neutral with a
> drift line, or ride on a deco station, such as in NE hanging on a line in
> the current.) plus in open sea one is never completely at rest as in a ca=
ve
> type deco environment. Also some divers occasionally vary more than a cou=
ple
> of feet at some point during a deco schedule. AGAIN another reason for
> looking closely at the 20 foot oxygen stop in a training program where th=
e
> student is being taught all these procedures
tom - use a jon line.it works and works well.for all of my open ocean
deco i use a jon line and find that i stay at the same depth +- 1' in the
water column.if you actually did any diving you'd understand that.and,for
the really big waves,what the hell are you doing sending students out in 8'
seas anyway?
>=20
> Options then became:
> 1. design in a 15 foot stop for the use of oxygen
> 2. Look at a EANx mixture for the stops that is significantly higher than
> the bottom mix and one that will also allow a faster decompression schedu=
le
> to reduce the hypothermia and dehydration problems as well and still prov=
ide
> good off gassing
>=20
> After reviewing these options and discussing them with several hyperbaric
> physicians and physiologist we elected to go to a high EANx mixture. Thus
> EAN 80 was selected.
this is the single most stupidest comment you have ever made.with pure
oxygen you have the option of doing a deco abort.you can treat bends on the
surface.you can treat any other diving injury on the surface.you can do all
of your deco at 20' to accelerate the decompression by keeping the oxygen
window open.on the hypothermia issue if you did the correct deco rather the=
n
the jabba deco for your bounce dives maybe you would not get so cold?i coul=
d
go on and on but it would just show your complete ignorance of
decompression,physiology,and oxygen and i do not want to embare-ass you.
> Two sets of tables in a variety of mixtures both Nitrox and trimix were
> designed
> Based on either EAN 75 or 78 with the intended gas being EAN 80.
> One set begins the EAN 80(75) at 20 feet the other begins at 30 feet
> So all current IANTD tables offered feature these mixes in technical
> programs. In recreational Advanced EANx we use EAN 50 for safety or requi=
red
> stops in the process of acquainting divers with the advantage of having m=
ore
> oxygen in the safety or real stop gas than what is in the bottom mix. In =
the
> intermediate trimix program we have a set of tables with one gas switch. =
The
> switch on that table is to EAN 70 at forty feet.
EAN 70 at 40' is a ppo2 of 1.6.what is the difference between 1.6 at
40',30'or 20'?or is this part of the pied piper in the sky bullshit that yo=
u
guys are famous for?and what depth do you start using EAN 50?
> The intent of these tables is to eliminate a need for a diver to be expos=
ed
> to a PO2 of 1.6 and also to stay within the oxygen exposure limits.
tom your tables expose the diver to a ppo2 of 1.6.ean 70 at 40' is a ppo=
2
of 1.6.ean 80 at 30' is a ppo2 of 1.6.ean 50 at 70' is a ppo2 of 1.6.and ho=
w
do you make sure that your ean 80/70/50 gases are correct?do you use a
chemical analyzer that is only valid within 2%?100% oxygen is just
that,100%.you fill an empty bottle with pure oxygen,what do you get?
> As stated these tables were developed for training program use. Even the
> trimix tables stay within the confines of two gas switches and do not
> involve bottom times such as encountered on exploratory dives.
> No one has stated that EAN 80 is a better choice for a deco gas, it is on=
e
> we think is more suitable for divers in a training program where they are
> involved with learning a lot of new skills and both gas and equipment
> management techniques
"no one has ststaed that ean 80 is a better choice for deco gas,it is wha=
t
we think is more suitable".excuse me?re-read what you just said then admit
the fact that you don't have a clue and the body count is piling up on your
doorstep to prove it.
> It is for these reasons that IANTD endorses EAN 80 as a training deco mix=
=2E
if you had a clue you wouldn't be saying such stupidity.
> Now you brought up the boat emergency gas, IANTD does not endorse EAN 80 =
as
> an emergency gas for the boat use, we think all boats should have oxygen
> available for emergency use. While its is important for both recreational
> and technical diving it is especially true for recreational diving where =
the
> risk and occurrence of AGE is greater than in technical diving. I repeat =
it
> is IANTD=92s opinion that charter boats should have 100% oxygen available=
as
> an emergency gas for diving accidents.
tom tell me the body count of iantd instructors for 1998 then tell me
the percentage of total students worldwide that are certified by iantd
instructors (for any course),then tell me the body count for naui
instructors in 1998,and the percentage of total students worldwide that are
certified by naui instructors,then try and tell me with a straight face tha=
t
technical diving training is safer then openwater training.
8 years ago i would have agreed with you because people seeking technica=
l
diver training were already divers who had beend iving.but now people
seeking technical diver training quite often have minimal diving experience
(the one your agency killed in west palm beach did not meet the entrance
requirements for for the course).when agencies such as yours propagandize
technical diving to draw in students (i love the 'nitrox it,dive it,trimix
it,dpv it,iantd it,love it' shirt) and increase reveniews the death toll
will increase.last year tdi was in the forefront,but now in 4 months you've
managed to outdo them.what will the next 8 months bring?what happened to th=
e
old credo of not advertising for students in technical (cave originally)
diving?you are whoring our sport and the body count is starting to rise,onl=
y
before where it was people going off experimenting with this on their
own,now it's people enrolled in your classes who are dying.
> Now on deco bottles they must be labeled per IANTD standards
i won't bother replying to this since it's obvious that you have your
fingers in your ears and aren't listening.for anyone who wants to know how
to do it right,check bentleys web site.
> Again IANTD is a training organization and our standards are based on and
> continually updated on those things we feel will provide the maximum safe=
ty
> to the students in a course.
does this mean you're going to start referring them to other agencies to
provide the students the maximum safety in a course?it is obvious that a
frighteningly large number of your instructors have no business teaching
technical diving and dont actually do any technical diving and have no
understanding,so it would make sense that the safest way for these students
to take a technical diving class would be to avoid iantd. - dick
--
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