Q: If I miss my deco-stop?
Patrick H. Beech
DecomChepot Astrajingga wrote:
>
> Dear fellow divers,
>
> When the first time I learn to SCUBA dive my instructor told me that,
> if I have to do a deco-stop but, but I miss it (out of air eg.), I can
> get out of the water get another tank and go back underwater doing the
> deco-stops that I miss but deeper and longer. Considering I have no
> symptoms of decompression sickness. Is it true?
>
> If it's true how deep and how long should my new deco-stop be?
>
> If it's not true, what is the best thing to do if I miss my deco-stop,
> but I don't get decompression sickness.
>
> Many thanks for your thoughts and opinions in advance.
>
> Chepot Astrajingga.
______________
The answer is not whether to come out of the water, get a tank, and go
back in. Decompression diving for sport divers is not the best type of
diving to do to begin with, but if you are so inclined, one of the most
commonsense approaches not to have happen what you envision is to tie a
full tank with regulator attached at, say the 15' mark, on a vertical
line (you are using a line to mark decompression stops aren't you -
depth guages aren't real accurate at those depths) and then you have air
available. Plan, plan, plan for contingincies, follow your dive plan,
and you will be okay.
Powerguy
Chepot Astrajingga
Mark Melendez
if you miss a stop and surface it's not a good idea to jump back in. if
i'm correct, padi says to breathe O2 at the surface and discontinue
diving for 24 hrs. if your ascending and forget to make a stop one good
rule of thumb is to stop at 15' and breathe your tank till it's almost
dry.
Paul Baran
Mark Melendez <SUB...@worldnet.att.net> wrote:
>if you miss a stop and surface it's not a good idea to jump back in. if
>i'm correct, padi says to breathe O2 at the surface and discontinue
>diving for 24 hrs. if your ascending and forget to make a stop one good
>rule of thumb is to stop at 15' and breathe your tank till it's almost
>dry.
Absolutely. You just add more nitrogen to your system by going back
down.
Paul Baran
Kevin-Neil Klop
In article <3252F6...@worldnet.att.net>, Mark Melendez
<SUB...@worldnet.att.net> wrote:
> if you miss a stop and surface it's not a good idea to jump back in. if
> i'm correct, padi says to breathe O2 at the surface and discontinue
> diving for 24 hrs. if your ascending and forget to make a stop one good
> rule of thumb is to stop at 15' and breathe your tank till it's almost
> dry.
::sigh:: There are many ideas about missed decompression stops. First of
all, remember that PADI states that you shouldn't NEED a decompression
stop because recreational diving is no-stop diving (no decompression stop,
that is). I.e. you should not ever be in a situation where you've
incurred a decompression stop.
If, for some reason, you do miss a stop, PADI rules state:
Breathe Pure O2 (or high concentrations of O2) on the surface, rest,
monitor yourself for signs/symptoms of DCS, no diving for 24 hours.
My own addition is to make sure that you remain well hydrated and do NOT
do any vigorous exercise (such as moving tanks around!).
The remaining information in this posting is not gospel... noone truly
understands DCS, what knowledge we have is the "it seems to work" variety
rather than the "we know why it works" variety - i.e. we're all still
experimenting on ourselves...
There are some people that claim that going back in the water is a bad
idea - that you're just adding more nitrogen to your body. This may or
may not be false depending on the circumstances. I'll have to go a little
into decompression theory (and I'll emphasize that it's "theory" not
"reality"!!)
If you have loaded up a "fast" tissue compartment sufficiently to cause a
required decompression stop, going back in the water will, likely,
continue to add nitrogen to a slow compartment while allowing offgassing
from the fast compartments. The whole idea of decompression stops is to
_regulate_ the offgassing of inert gasses. If being in the water always
added nitrogen then decompression stops would not be a possibility at
all. Thus, going back into the water for omitted decompression _may_ be
helpful.
The problem is that there are also very real risks to it. Thus, a
determination of when the risks of DCS if you stay on the surface outweigh
the inherent risks of in-water recompression. For 99.999999% of the
divers out there, the risks of in-water recompression outweigh the risks
of DCS at all times. Very few people are set up to do IWR in a reasonably
safe manner. Even if someone on the boat IS set up for it, very few
people reading this have the necesary skill to do it. Thus, "acceptable"
risk is the intersection of the set of people with the skill and the set
of people equipped for it.
My suggestion to everyone is to follow the PADI guidelines (i.e. stay on
the surface, breathe the highest concentration of O2 that you can find,
monitor for signs/symptoms of DCS, with my additions). DCS is rarely
fatal. Drowning often is.
-- Kevin --
--
Death is not a problem. Fear of death is.
Lee Bell
Mark Melendez <SUB...@worldnet.att.net> wrote:
> >if you miss a stop and surface it's not a good idea to jump back in. if
> >i'm correct, padi says to breathe O2 at the surface and discontinue
> >diving for 24 hrs. if your ascending and forget to make a stop one good
> >rule of thumb is to stop at 15' and breathe your tank till it's almost
> >dry.
> Paul Baran wrote:
> Absolutely. You just add more nitrogen to your system by going back
> down.
Sorry Paul, but you're a bit off base on this one. If you reqired a deco stop at 20 feet (just an example), it
means that the nitrogen in your system was at a level greater than saturation at 20 feet. Returning to 20 feet
immediately does not add nitrogen to your system, you'll still be offgassing. Same thing applies to deeper
required stops. On the other hand, returning to the stop immediately may inhibit continued bubble formation,
perhaps resulting in bubbles large enough to cause tissue damage or worse yet, block circulation to critical
organs, such as the heart or brain.
Most experts advise that someone who misses a decompression stop return immediately to complete decompression.
After a period, it's no longer recommended, but never having missed a stop, I'm sorry to say I can't remember
what the interval is. The idea of an extended stop at 15 feet appeals to me. But then, my normal stop is 2
minutes at 20 feet and 3 at 15. I'm easy enough on air to have plenty for the extra stop and reluctant enough
to leave the water to enjoy the extra down time.
Lee
Lee Bell
Kevin-Neil Klop wrote:
>Thus, going back into the water for omitted decompression _may_ be helpful.
> The problem is that there are also very real risks to it. Thus, a
> determination of when the risks of DCS if you stay on the surface outweigh
> the inherent risks of in-water recompression. For 99.999999% of the
> divers out there, the risks of in-water recompression outweigh the risks
> of DCS at all times.
Hmmmm, I agree with all your discussion, but not your conclusion. Interesting. It is my opinion that simply
missing a stop and returning immediately to complete the process is not "recompression". As you noted, and I
stated in the response I made before reading yours, a decompression stop is intended to allow gradual
offgassing of critical tissues. Assuming a very short interval at the surface, returning to the missed stop is
likely to continue the offgassing process rather than load, at least as far as the critical tissue is
concerned.
The situation I envision is a distressed buddy. There may be circumstances where a buddy needs to make a trip
all the way to the surface, missed stops or not. Assuming someone to hand the buddy off to at the boat, I can
envision taking a buddy up, handing them off to those who can provide assistance and returning to complete my
decompression obligation.
Where we agree 100% is that once a person who missed a stop has been on the surface long enough to form
significant bubbles, probably a matter of minutes, returning to make the stop is a very poor idea. This is
what I refer to as "recompression". It's also what Mike Nelson used to do on Sea Hunt. It's about the only
thing I can remember that he did which we now know is seriously dangerous. Then again, recompression chambers
weren't in every major U.S. city then either.
Lee
Dillon Pyron
Lee Bell wrote:
>
> Mark Melendez <SUB...@worldnet.att.net> wrote:
>
> > >if you miss a stop and surface it's not a good idea to jump back in. if
> > >i'm correct, padi says to breathe O2 at the surface and discontinue
> > >diving for 24 hrs. if your ascending and forget to make a stop one good
> > >rule of thumb is to stop at 15' and breathe your tank till it's almost
> > >dry.
If you are going to start with PADI rules, you should stick with them.
Follow the guidlines on the RDP/Wheel. Of course, if we were following
them, we wouldn't be talking about deco stops, would we :-)
>
> > Paul Baran wrote:
>
> > Absolutely. You just add more nitrogen to your system by going back
> > down.
>
> Sorry Paul, but you're a bit off base on this one. If you reqired a deco stop at 20 feet (just an example), it
> means that the nitrogen in your system was at a level greater than saturation at 20 feet. Returning to 20 feet
> immediately does not add nitrogen to your system, you'll still be offgassing. Same thing applies to deeper
> required stops. On the other hand, returning to the stop immediately may inhibit continued bubble formation,
> perhaps resulting in bubbles large enough to cause tissue damage or worse yet, block circulation to critical
> organs, such as the heart or brain.
>
> Most experts advise that someone who misses a decompression stop return immediately to complete decompression.
> After a period, it's no longer recommended, but never having missed a stop, I'm sorry to say I can't remember
> what the interval is. The idea of an extended stop at 15 feet appeals to me. But then, my normal stop is 2
> minutes at 20 feet and 3 at 15. I'm easy enough on air to have plenty for the extra stop and reluctant enough
> to leave the water to enjoy the extra down time.
The recommended interval is 5 to 10 minutes, depending on who is
talking. The rationale is that after that point, you are in a position
of actually having DCI symptoms, including (inconveniently) loss of
conciousness. So, you hit the surface, say a naughty word and drop back
down. Or, you hit the surface, get out, rinse your gear and say "Oh, my
computer says DECO VIOLATION YOU FOOL" and then you start on O2 while
the boat heads home and your dive buds take your name in vain.
Three to five minutes at 15 ft works nicely for me. Deeper dives mean
deeper and longer stops (as well as something at 15) for me.
But everyone MUST use his/her own judgement.
--
dillon pyron
dillon...@amd.com
PADI OWSI-54909 USPSA TY-26031
"I can only take two of you, so why don't those two step up and get this
out
of the way".
Andrew L. Jenks
Lee Bell (lee...@ix.netcom.com) wrote:
: Most experts advise that someone who misses a decompression stop return immediately to complete decompression.
: what the interval is.
Two and a half minutes is what I remembering, but does anyone know
where this number comes from? Seems like it's the amount of time
in the Navy manual for a diver to get out of the water and into
the chamber. Anyone? Beuler?
: The idea of an extended stop at 15 feet appeals to me. But then, my normal stop is 2
: minutes at 20 feet and 3 at 15. I'm easy enough on air to have plenty for the extra stop and reluctant enough
: to leave the water to enjoy the extra down time.
: Lee
--
Andrew L. Jenks
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!vaps5aj
Internet: vap...@prism.gatech.edu
Barb Marshall Services
In article <531kgl$h...@condor.cns.iit.edu> ALUMP...@minna.iit.edu (John Pezdek) writes:
>From: ALUMP...@minna.iit.edu (John Pezdek)
>Subject: Re: Q: If I miss my deco-stop?
>Date: 4 Oct 1996 00:07:49 GMT
It's been a while since I looked at my manual but I believe the aborted deco
procedure outlined is from the treatment section of the book which would
call for an extra 4 minutes (slow 1 minute ascent between stops)
The DCIEM manual requires that you do the first missed stop 10 feet deeper and
then go back on your profile. eg. if you missed 5@20' and 10@10' you would
do 5@30', 5@20' and 10@10' assuming that you could be back in the water
within 5 minutes and had no symtoms.
>My copy of the US Navy Dive Manual states
(with no symptoms):>- Repeat any stops deeper than 40 feet.>- At 40 feet,
remain for 1/4 of the 10-foot stop time.>- At 30 feet, remain for 1/3 of the
10-foot stop time.>- At 20 feet, remain for 1/2 of the 10-foot stop time.>- At
10 feet, remain for 1 and 1/2 times the scheduled 10-foot stop time.
>In article <531h17$8...@catapult.gatech.edu>, vap...@acmex.gatech.edu says...
John Pezdek
Paul Baran
Lee Bell <lee...@ix.netcom.com> wrote:
>> Paul Baran wrote:
>> Absolutely. You just add more nitrogen to your system by going back
>> down.
>Sorry Paul, but you're a bit off base on this one.... If you reqired a deco stop at 20 feet (just an example), it
>means that the nitrogen in your system was at a level greater than saturation at 20 feet. Returning to 20 feet
>immediately does not add nitrogen to your system, you'll still be offgassing.
Hi Lee,
Point taken on the depth/saturation issue, thanks. I had somehow got
the impression that our diver had spent quite some time on the
surface.
Cheers,
Paul
Eric Reynaud
Mark Melendez wrote:
>
> Chepot Astrajingga wrote:
> > When the first time I learn to SCUBA dive my instructor told me that,
> > if I have to do a deco-stop but, but I miss it (out of air eg.), I can
> > get out of the water get another tank and go back underwater doing the
> > deco-stops that I miss but deeper and longer. Considering I have no
> > symptoms of decompression sickness. Is it true?
>
> i'm correct, padi says to breathe O2 at the surface and discontinue
> diving for 24 hrs. if your ascending and forget to make a stop one good
> rule of thumb is to stop at 15' and breathe your tank till it's almost
> dry.
In a real emergency (rocketting to the surface due to panic or lost of
boyancy control, or any other reason) the following safety procedure
can be applied (assuming that you don't get a pulmonary barotrauma during
this ascent):
1) Get a full tank WITHIN LESS THAN 3 MINUTES,
2) Descend to HALF the max depth you reached during the dive.
3) Spend 5 minutes at this depth
4) Ascend slowly (17m/minute max) at the first deco-stop
(you have had 5 minutes to determine which one).
5) Make you're deco-stops taking into account the depth of the 1st dive and the
total time of the 1st dive (from surface to surface) + 3 minutes(max) on the boat
+ time from surface to half-depth + 5 minutes.
This procedure must remain exceptional, and IS NOT A GUARANTEE that no DCS will
happen: it just lower the impact when the risks are very high (deep diving, long
time), but does not mean that you will not require an hyperbaric O2 treatment.
If you surface too far from the boat to be able to get new tank in less than 3
minutes, you're a perfect candidate for the hyperbaric chamber.
In the case where you made a normal ascend, started you're deco-stop but had to abend
due to loss of air, a similar procedure applies:
1) get a full tank WITHIN LESS THAN 3 MINUTES.
2) descend to the DEPTH of YOUR FIRST DECO-STOP (if several)
3) Restart your deco-stops from the beginning.
Once again, this procedure is not a guarantee, and should be avoided by better dive
planning, and spare tank at the deco-step.
For both cases, breathing 100% O2 and avoiding diving for 24 hours are a good advice.
--
Eric
The opinions are those of the writer, not of Rohm and Haas Company.
Brian Raskin
This is one of the things about this list that cracks me up. Someone asks
a fairly simple question, and receives billions of answers to a question
not-yet-asked.
Safety stops and decompression stops are very very different. Safety
stops come from a PADI NDL table. Decompression stops are obligations
based on Deco Tables designed to avoid DCS or DCI, whichever you wish to
call it.
A missed safety stop is not a call for an extreme emergency, especially
when an out of air situation was the option. Relax, breathe O2 and watch
for the extremely unlikely signs of DCS.
A missed Deco obligation means a trip to a hospital or care unit which
houses a recompression chamber.
Its about that simple.
Kuty
Lee Bell <lee...@ix.netcom.com> wrote:
>Kevin-Neil Klop wrote:
>>Thus, going back into the water for omitted decompression _may_ be helpful.
>> The problem is that there are also very real risks to it. Thus, a
>> determination of when the risks of DCS if you stay on the surface outweigh
>> the inherent risks of in-water recompression. For 99.999999% of the
>> divers out there, the risks of in-water recompression outweigh the risks
>> of DCS at all times.
>Hmmmm, I agree with all your discussion, but not your conclusion. Interesting.
>It is my opinion that simply
>missing a stop and returning immediately to complete the process is not
>"recompression". As you noted, and I
>stated in the response I made before reading yours, a decompression stop is intended
>to allow gradual
>offgassing of critical tissues. Assuming a very short interval at the surface, returning
>to the missed stop is
>likely to continue the offgassing process rather than load, at least as far as the critical
> tissue is concerned.
I think that both Lee and Kevin have the same opinion and the same
conclusion. The difference is that Kevin is not recommending that
divers should follow this procedure because he is not sure whether
they can complete it unharmed.
If you look at the first sentence in Kevin's quote here you see:
"Thus, going back into the water for omitted decompression _may_ be
helpful."
I read it: "If I happend to be in this situation with no chamber in
the area I would have gone into the water,". The rest of the quote
just says:"Don't try it at home. It's dangerous and you may die
faster, trying to do it than staying on board, breathing O2 and
rushing to the nearest chamber."
The difference between *succeeding* to pull a recompression stunt and
skipping one while waiting to get to a chamber can result in a long
time of chamber treatments in severe and unpleasent symptoms.
The difference between *failing* to pull a recompression stunt and
skipping one is between death and life.
Regards,
Kuty
Lars Johansson
>In a real emergency (rocketting to the surface due to panic or lost of
>boyancy control, or any other reason) the following safety procedure
>can be applied (assuming that you don't get a pulmonary barotrauma during
>this ascent):
>
>1) Get a full tank WITHIN LESS THAN 3 MINUTES,
>2) Descend to HALF the max depth you reached during the dive.
>3) Spend 5 minutes at this depth
>4) Ascend slowly (17m/minute max) at the first deco-stop
> (you have had 5 minutes to determine which one).
>5) Make you're deco-stops taking into account the depth of the 1st dive and the
> total time of the 1st dive (from surface to surface) + 3 minutes(max) on the boat
> + time from surface to half-depth + 5 minutes.
I would like to add the following piece of advice, *if* you
decide to go down to do a missed deco stop:
1) don't go down alone, since you might need help if
you develop dcs or other medical problems.
2) If you have already developed dcs or other symptoms,
don't go down again. (Unless you have a *very* high level of
surface support from people who *really* know how to
pull of such a stunt).
Doug/Susan Lyvere
J Shepherd wrote:
>
> lala**@lili.net.id (Chepot Astrajingga) writes:
>
> >Dear fellow divers,
>
> >When the first time I learn to SCUBA dive my instructor told me that,
> >if I have to do a deco-stop but, but I miss it (out of air eg.), I can
> >get out of the water get another tank and go back underwater doing the
> >deco-stops that I miss but deeper and longer. Considering I have no
> >symptoms of decompression sickness. Is it true?
>
>
> >If it's not true, what is the best thing to do if I miss my deco-stop,
> >but I don't get decompression sickness.
>
> >Many thanks for your thoughts and opinions in advance.
>
> >Chepot Astrajingga.
>
> and remain calm, and observe for symptoms. Alert the nearest chamber and
> follow the given advice.
>
> If >6 hours, it's a lottery. Various procedures are documented,
> try a web search engine and 'Rich Pyle' to see if anyone has posted up
> his article on the subject. Rich has succesfully used IWR, and it was
> also part of a 6month recovery process involving paralysis. Not funny.
>
> If >6 hours from a chamber and intending to get into deco
> diving, read up and consider your options. Have plenty of o2 available,
> and preferably an FFM.
>
> Finally, consider that for simple exposures (single dives,
> square profile) most tables in common use (and computers) are
> conservative, and considerable amounts of deco can be missed by *most*
> people before the risk of DCI becomes appreciable. Weigh that against
> the fact that immediately reentering the water after any dive, even a no
> stop one, has a risk of *inducing* DCI and you can see the mess. IWR has
> worked, it has also killed people. It is successful when properly
> organised as a contigency plan.
>
> Surface O2, communication and transport to a chamber comprise a
> better response in many, if not most, situations.
>
> As for the agency line, BSAC strongly advise against reentering
> the water to resume stops. It has a history of not working in UK waters
> (too cold, weather too bad, tides too strong) and we have very good
> recompression facilities, and a *very* good air/sea rescue and
> coastguard set up. On the house, as it were. Thank God.
>
> Of course, they'll try to privatise that next...
>
> Jason
>
> (ON-U sound - privatise the air; a salutary lesson)
It partially depends on which source you wish to listen to. If using
and beleiving in the Navy tables, the Navy tables state:
after getting a new air supply and a set of tables, redescend to:
1) 50' for 1/5th the 10' stop time, then
2) 40' for 1/4th the 10' stop time, then
3) 30' for 1/3rd the 10' stop time, then
4) 20' for 1/2 the 10' stop time, then
5) 10' for 1 and 1/2 times the 10' stop time. then pray
Sorry, last comment mine. Best solution is to dive carefully and not
put yourself into this situation. I'm sure that there are at least a
half dozen quoted solutions, I'm just reading the one. Good luck and
dive safely. Doug
Dale Firmin
J Shepherd wrote:
> Finally, consider that for simple exposures (single dives,
> square profile) most tables in common use (and computers) are
> conservative, and considerable amounts of deco can be missed by *most*
I disagree...The original Navy dive tables were developed for young
males with peak athletic ability. The recreational tables were changed
recently due to doppler studies. They are in no way conservative. Some
dive computers use the tables as their "models" (Suunto SME-USN and
Decobrain I are such computers). "Pushing" a table or computer is
asking for trouble. Conditions have to be ideal for the computer or
table to be accurate. Temperature, exertion, state of hydration, carbon
dioxide retention, all play a part. There is a risk of following a
table perfectly and still getting bent even under the most ideal
situations. It's a risk we should all know and we all take.
That's my only disagreement.
Dale
Brian Nadwidny
Chepot Astrajingga wrote:
>
> Dear fellow divers,
>
> When the first time I learn to SCUBA dive my instructor told me that,
> if I have to do a deco-stop but, but I miss it (out of air eg.), I can
> get out of the water get another tank and go back underwater doing the
> deco-stops that I miss but deeper and longer. Considering I have no
> symptoms of decompression sickness. Is it true?
>
> If it's true how deep and how long should my new deco-stop be?
>
> If it's not true, what is the best thing to do if I miss my deco-stop,
> but I don't get decompression sickness.
>
> Many thanks for your thoughts and opinions in advance.
>
> Chepot Astrajingga.
My thoughts are that you should take the appropriate level of training
with an appropriate agency that will enable you to answer this question
on your own and to ignore anything that you have read in the newsgroup.
--
Brian Nadwidny IANTD Instructor, SSI Instructor, PADI DM
Edmonton, Alberta,Canada
nadw...@agt.net
7435...@compuserve.com
J Shepherd
lala**@lili.net.id (Chepot Astrajingga) writes:
>Dear fellow divers,
>When the first time I learn to SCUBA dive my instructor told me that,
>if I have to do a deco-stop but, but I miss it (out of air eg.), I can
>get out of the water get another tank and go back underwater doing the
>deco-stops that I miss but deeper and longer. Considering I have no
>symptoms of decompression sickness. Is it true?
>If it's true how deep and how long should my new deco-stop be?
>If it's not true, what is the best thing to do if I miss my deco-stop,
>but I don't get decompression sickness.
>Many thanks for your thoughts and opinions in advance.
>Chepot Astrajingga.
If you are <6 hours from a chamber, get onto surface O2, relax
and remain calm, and observe for symptoms. Alert the nearest chamber and
follow the given advice.
If >6 hours, it's a lottery. Various procedures are documented,
try a web search engine and 'Rich Pyle' to see if anyone has posted up
his article on the subject. Rich has succesfully used IWR, and it was
also part of a 6month recovery process involving paralysis. Not funny.
If >6 hours from a chamber and intending to get into deco
diving, read up and consider your options. Have plenty of o2 available,
and preferably an FFM.
Finally, consider that for simple exposures (single dives,
square profile) most tables in common use (and computers) are
conservative, and considerable amounts of deco can be missed by *most*
Chuck Narad
In article <3257FF...@mail.idt.net>, Dale Firmin <dal...@mail.idt.net> writes:
> J Shepherd wrote:
> > Finally, consider that for simple exposures (single dives,
> > square profile) most tables in common use (and computers) are
> > conservative, and considerable amounts of deco can be missed by *most*
> > people...
>
> I disagree...The original Navy dive tables were developed for young
> males with peak athletic ability.
the navy tables also assumed the presence of a chamber and attending
physician, and had (if I recall correctly) an expected DCI hit
rate of around 5%.
and while the tables were intended for healthy young males, the chamber
experiments were done with the next best thing: goats :-)
c/
> The recreational tables were changed
> recently due to doppler studies. They are in no way conservative. Some
> dive computers use the tables as their "models" (Suunto SME-USN and
> Decobrain I are such computers). "Pushing" a table or computer is
> asking for trouble. Conditions have to be ideal for the computer or
> table to be accurate. Temperature, exertion, state of hydration, carbon
> dioxide retention, all play a part. There is a risk of following a
> table perfectly and still getting bent even under the most ideal
> situations. It's a risk we should all know and we all take.
>
> That's my only disagreement.
>
> Dale
>
--------------------------------------------------------------------
| Chuck Narad -- diver/adventurer/engineer |
| |
| "Yesterday is history. Tomorrow is a mystery. And today? |
| Today is a gift. That's why we call it The Present." |
| - Babatunde Olatunji |
--------------------------------------------------------------------
Tim Gaston
kev...@apple.com (Kevin-Neil Klop) wrote:
>The problem is that there are also very real risks to it. Thus, a
>determination of when the risks of DCS if you stay on the surface outweigh
>the inherent risks of in-water recompression. For 99.999999% of the
>divers out there, the risks of in-water recompression outweigh the risks
>of DCS at all times. Very few people are set up to do IWR in a reasonably
>safe manner. Even if someone on the boat IS set up for it, very few
>people reading this have the necesary skill to do it. Thus, "acceptable"
>risk is the intersection of the set of people with the skill and the set
>of people equipped for it.
True. I agree with your reasoning and your conclusion. I would also
add one point to the debate.
The discussion so far seems to assume that in the event a diver did go
back down to finish a stop then there would no longer be any
possibility of suffering a bend. A failsafe cure so to speak.
Unfortunately this has not always been shown to be the case. A bend
can arise even after an attempt to complete a stop and by going down
again you will exacerbate the problem that the recompression chamber
operatives will have in determining a suitable treatment schedule.
Jeff Stillinger
In article <325878...@popd.ix.netcom.com>, Doug/Susan Lyvere (pen...@popd.ix.netcom.com) writes:
>J Shepherd wrote:
>>
>> lala**@lili.net.id (Chepot Astrajingga) writes:
>>
>> >Dear fellow divers,
>>
>> >When the first time I learn to SCUBA dive my instructor told me that,
>> >if I have to do a deco-stop but, but I miss it (out of air eg.), I can
>> >get out of the water get another tank and go back underwater doing the
>> >deco-stops that I miss but deeper and longer. Considering I have no
>> >symptoms of decompression sickness. Is it true?
>>
>> >If it's true how deep and how long should my new deco-stop be?
>>
>> >If it's not true, what is the best thing to do if I miss my deco-stop,
>> >but I don't get decompression sickness.
>>
>> >Many thanks for your thoughts and opinions in advance.
>>
>> >Chepot Astrajingga.
>>
>> If you are <6 hours from a chamber, get onto surface O2, relax
>> and remain calm, and observe for symptoms. Alert the nearest chamber and
>> follow the given advice.
>>
>> If >6 hours, it's a lottery. Various procedures are documented,
>> try a web search engine and 'Rich Pyle' to see if anyone has posted up
>> his article on the subject. Rich has succesfully used IWR, and it was
>> also part of a 6month recovery process involving paralysis. Not funny.
>>
>> If >6 hours from a chamber and intending to get into deco
>> diving, read up and consider your options. Have plenty of o2 available,
>> and preferably an FFM.
>>
>> square profile) most tables in common use (and computers) are
>> conservative, and considerable amounts of deco can be missed by *most*
>> the fact that immediately reentering the water after any dive, even a no
>> stop one, has a risk of *inducing* DCI and you can see the mess. IWR has
>> worked, it has also killed people. It is successful when properly
>> organised as a contigency plan.
>>
>> Surface O2, communication and transport to a chamber comprise a
>> better response in many, if not most, situations.
>>
>> As for the agency line, BSAC strongly advise against reentering
>> the water to resume stops. It has a history of not working in UK waters
>> (too cold, weather too bad, tides too strong) and we have very good
>> recompression facilities, and a *very* good air/sea rescue and
>> coastguard set up. On the house, as it were. Thank God.
>>
>> Of course, they'll try to privatise that next...
>>
>> Jason
>>
>> (ON-U sound - privatise the air; a salutary lesson)
>and beleiving in the Navy tables, the Navy tables state:
>after getting a new air supply and a set of tables, redescend to:
> 1) 50' for 1/5th the 10' stop time, then
> 2) 40' for 1/4th the 10' stop time, then
> 3) 30' for 1/3rd the 10' stop time, then
> 4) 20' for 1/2 the 10' stop time, then
> 5) 10' for 1 and 1/2 times the 10' stop time. then pray
>Sorry, last comment mine. Best solution is to dive carefully and not
>put yourself into this situation. I'm sure that there are at least a
>half dozen quoted solutions, I'm just reading the one. Good luck and
>dive safely. Doug
>
I think that the best thing was said, and I should stress it. Dive
carefully and DO NOT put yourself into this situation! Look, if you
get bent because you did something stupid, then you got what was
comeing. You deserve everything you get. How many times have students
been told PLAN YOUR DIVE, DIVE YOUR PLAN!
This weekend I went diving and I could not belive my eyes. Divers
WITHOUT dive tables! Divers on the boat where getting dressed before
the divemaster had a chance to breif the dive site. All types of other
unsafe things where going on with diving as well. Beer at lunch
really amazed me. Granted dive boats are expensive and maximizing your
day is always a top priority. But hey, plan your dive. Pay attention
to what the divemaster has to say about the site. How deep it is
etc... Make a plan not to dive deeper than 'X' amount of feet. Get
your hand signals down, look at your buddy and how his equipment is
configured. Then stick to that plan. I would have loved to gotten
down to the wreck, but it was deeper than what we had planed on. So,
there is always next time. The scallops where better eating than the
wreck was any day!
Now who do I personally hold accountable for the unsafe diving? The
divers! The divemaster, and boat captin can only give you pointers.
You are the one that is diving, breathing, and responsible for your
actions.
--js
-
--
---
- ----
--- ------
-THEY DON'T GET OFF TIL WE COME>
--- ------
- ----
---
--
-
-
s951...@babel.ee.up.ac.za
A reason why you musn't get back in once you've missed your deco stop is
because although you might not feel the symptoms as you get another tank,
Decompression Sickness can hit you anytime, like on your way down. If this
does happen, there are chances that you "black out" underwater which is
NOT good. This won't happen all the time, but it could just happen to you,
so rather stay on the surface, breath O2 and if possible get to a
decompression tank.
Al
**
aa
na...@nudibranch.asd.sgi.com,news wrote at 0:50 on 8/10/96
to rec.scuba about "Re(3): Q: If I miss my deco-stop?".
If you miss a stop and you aren't bent, it's best to get close to a
chamber
just in case. Don't ever go back in the water, it's a cold,
uncontrolled,
dangerous environment and no place to treat what could be a serious
condition.
As a precaution, whilst getting to a chamber, breath O2, take aspirin
(which inhibits blood clotting around gas bubbles in the bloodstream),
drink a lot so you can dump nitrogen through your urine, and relax.
Exercise can
make the micro-bubbles that are always present after a dive coalesce
and
start to cause problems. And don't fly above 300m or drive over high
muntain passes. The pressure drop might jusr be enough to start a bend.
Paul Williams
--- OffRoad 1.9e registered to Paul Williams
Bernard Flank
> >> lala**@lili.net.id (Chepot Astrajingga) writes:
> >>
> >> >Dear fellow divers,
> >>
> >> >When the first time I learn to SCUBA dive my instructor told me that,
> >> >if I have to do a deco-stop but, but I miss it (out of air eg.), I can
> >> >get out of the water get another tank and go back underwater doing the
> >> >deco-stops that I miss but deeper and longer. Considering I have no
> >> >symptoms of decompression sickness. Is it true?
> >>
> >> >If it's true how deep and how long should my new deco-stop be?
> >>
> >> >If it's not true, what is the best thing to do if I miss my deco-stop,
> >> >but I don't get decompression sickness.
The Navy Diving Manual Volume I, Section 8-13 gives guidance for omitted decompression.
This is probably the best researched advice available. Of course as others have pointed
out, the best advice is to not omit the decompression in the first place.
Very abbreviated summary:
Ascent from 20' or shallower- if the diver surfaced from 20' or shallower, feels well,
and can return to stop depth within 1 minute the diver may complete normal decompression
stops. The stop from which ascent occurred is lengthened by one minute. If the 1
minute surface interval is exceeded and the diver remains asymptomatic, return the diver
to the stop from which the diver ascended and multiply the 20' and/or 10' stops by 1.5.
Alternatively treat in a recompression chamber on Treatment Table 5 or 1A. The diver
should be observed for 1 hour after surfacing or completing treatment.
Ascent from deeper than 20'- Treat in a recompression chamber if available. If no
chamber is available use the following procedure to make up omitted decompression in
asymptomatic divers. Recompress as soon as possible. Keep the diver at rest, provide a
standby diver, and maintain good communications and depth control. Use the
decompression schedule appropriate for the divers depth and bottom time.
1. Return the diver to the depth of the first stop.
2. Follow the schedule for stops 40' or deeper.
3. Multiply the 30',20', and 10' stops by 1.5
In water recompression treatment is a touchy business. Doing it without some help in
the form of other divers to monitor the diver(s) being treated is probably (in my
opinion) more hazardous than waiting to reach a recompression facility. Another post
recommended use of surface O2 - excellant idea - green gas is good gas.
Regarding the "conservative" nature of the tables, I was taught in Navy diving school
that if the tables were followed to the letter you could expect DCS in approximately 5%
of divers. Omitted "D" is nothing to be trifled with. Remember the 7 P's - Proper
Prior Planning Prevents P--- Poor Performance.
B.L. Flank
mike...@ix.netcom.com
My 2 cents:
I agree with Al. For recreational divers, in water decompression is, at
least in the States, a practice recommended by any agencies I am aware
of. I believe that even the Navy limits the time the diver can be out
of the water to no more than 5 min before going back in for
recompression.
Without getting into the "you shoulda known better" mode....I would add
that once out of the water...YOU tell the divemaster the specifics of
your days dive profiles. Make someone with training aware of the fact
you missed a stop.
Secondly, let's not forget DAN. Knowing the specifics of your condition
and profile, DAN is a worthwhile place to go for both medical advice
and guidance on the location of the neareset available chamber. If you
are no a member...it is a worthwhile investment.
Finally, to reemphasize what Al said.....starting on oxygen right away
and staying both warm and calm is good first aid. Pure oxygen will
promote the release of nitrogen from your system.
Finally, should you seek professional care....make sure that someone
trained in diving first aid goes along. MOST ambulance drivers and many
emergency room personnel are not trained in dive related injuries.
Someone trained in diving first aid might help save a lot of confusion
along the way...and hopefully...again...connect the medical staff with
the experts at DAN.
Cheers
Mike
J Shepherd
na...@nudibranch.asd.sgi.com (Chuck Narad) writes:
>In article <3257FF...@mail.idt.net>, Dale Firmin <dal...@mail.idt.net> writes:
>> J Shepherd wrote:
>> > Finally, consider that for simple exposures (single dives,
>> > square profile) most tables in common use (and computers) are
>> > conservative, and considerable amounts of deco can be missed by *most*
>> > people...
>>
>> I disagree...The original Navy dive tables were developed for young
>> males with peak athletic ability.
>the navy tables also assumed the presence of a chamber and attending
>physician, and had (if I recall correctly) an expected DCI hit
>rate of around 5%.
Call the statistician; I gather that 5% does not mean what you
and I would think it means... Generally, the hit rate seems to be 1
every 10e4-10e5 dives.
>and while the tables were intended for healthy young males, the chamber
>experiments were done with the next best thing: goats :-)
I think Haldane stuck to goats and his own family, but the navy
used real live people. Young fit males, though.
>c/
>> The recreational tables were changed
>> recently due to doppler studies. They are in no way conservative. Some
>> dive computers use the tables as their "models" (Suunto SME-USN and
>> Decobrain I are such computers). "Pushing" a table or computer is
>> asking for trouble. Conditions have to be ideal for the computer or
>> table to be accurate. Temperature, exertion, state of hydration, carbon
>> dioxide retention, all play a part. There is a risk of following a
>> table perfectly and still getting bent even under the most ideal
>> situations. It's a risk we should all know and we all take.
>>
The link between bubbles and diagnosed DCI is not mapped out. It
is *assumed* to be causal. Rather like it taking a *long* time to
*prove* that genetic inheritence was mediated by chromosomes. It is
generally accepted, but not proven. In fact, the high levels of doppler
signal which can be endured asymptomatically are used as evidence
against a simple bubble lesion model, and have lead to investigations of
PFO from a causal point of view, and an investigation of how bubbles
actually interact with the vascular system.
>> That's my only disagreement.
It's a very valid one; my point would rest on saying, I know
enough people who have missed enough stops that I would blow my last
five minutes and still feel unlucky to get a hit (say I was bringing a
casualty up, etc).
>>
>> Dale
>>
>--------------------------------------------------------------------
>| Chuck Narad -- diver/adventurer/engineer |
>| |
>| "Yesterday is history. Tomorrow is a mystery. And today? |
>| Today is a gift. That's why we call it The Present." |
>| - Babatunde Olatunji |
>--------------------------------------------------------------------
There is a line that is drawn. We don't know who drew it, or
what it means, but we stick to it like glue and we believe we'll get
through. - Hyperbaric Creed, Verse 21.
Jason :-)
Chuck Narad
In article <53gmc6$h...@scotsman.ed.ac.uk>, j...@holyrood.ed.ac.uk writes:
>
> >the navy tables also assumed the presence of a chamber and attending
> >physician, and had (if I recall correctly) an expected DCI hit
> >rate of around 5%.
>
> Call the statistician; I gather that 5% does not mean what you
> and I would think it means... Generally, the hit rate seems to be 1
> every 10e4-10e5 dives.
My copy of "Deeper Into Diving" just arrived, and I bet he digs into
the details on the navy tables; thanks for the heads-up, I'll
dig into this for my own edification!
cheers,
c/
Mr M.S. Foster
Brian Nadwidny (nadw...@agt.net) wrote:
: My thoughts are that you should take the appropriate level of training
: with an appropriate agency that will enable you to answer this question
: on your own and to ignore anything that you have read in the newsgroup.
Gosh common sense... now there's a thing. By the way, of the answers posted
to this question, a lot had the formula:
I don't remember exactly but i think it is like "go back in the water
to a depth of a half your max depth +5 and stay their for your normal
deco*2 +7 then ...
1/ Why post a half baked formula you can't quite remember that:
2/ A possibly paniced or nervous diver may not work out correctly or be
familiar with (after changing tanks/regulator in under 7 seconds) and
3/ may not be appropriate to the tables/certifying association that they
are diving with.
I think that you should think twice before recommending to a inexperianced
diver that the thing you should do if you fuck up is get back in the water.
I do appologise if the original poster wasn't a novice but others listening
surely are. There is good general advice you can give: Breath O2 or Nitrox,
be alert to the simptoms of dcs, Use your radio to alert the emergency
services etc etc. This sort of advice could do more harm than it fixes.
Cheerio,
Martyn Foster
Sensormatic
Another perceived danger of in-water recompression is that bubbles
lodged in the aveolar capilliaries shrink enough under pressure to come
loose, and then wind up in the arterial system en route to the brain
etc.
(Think I read that in Deeper into Diving).
Personally, I'd think long and hard about deco diving far from a
recompression facility. And then not do it.
--
Nick Simon
Gordon Gunn
And another thing...
When microbubbles begin to expand into "real" bubbles, they also begin to
glom (a technical term) together into even larger bubbles. Once that has
happened, simple recompression while breathing air will *not* shrink them
back down to microbubble size.
Gordon in Austin
VASI
aa wrote:
>
> If you miss a stop and you aren't bent, it's best to get close to a
> ... Don't ever go back in the water, it's ... a dangerous environment > and no place to treat what could be a serious condition.
>
> As a precaution, whilst getting to a chamber, breath O2, take aspirin...drink a lot...and relax.
This is what I was taught and the most reasonable thing to do from a
scientifical/medical point of view. Of course, there could be a
situation with no chamber available at short time in which you must use
your best judgement whether to inmerse again or not. Should you take the
second, all the suggestions above are still the sensible thing to do.
VASI, ACUC SP5223
"I can resist anything but temptation", O. W., LWf.
VASI
aa wrote:=20
> =20
> If you miss a stop and you aren't bent, it's best to get close to a=20
> chamber...=20
> ... Don't ever go back in the water, it's ... a dangerous environment=20
> and no place to treat what could be a serious condition.=20
> =20
> As a precaution, whilst getting to a chamber, breath O2, take=20
aspirin...drink a lot...and relax.=20
=20
This is what I was taught and the most reasonable thing to do from a=20
scientifical/medical point of view. Of course, there could be a=20
situation with no chamber available at short time in which you must use=20
your best judgement whether to inmerse again or not. Should you take the=20
second, all the suggestions above are still the sensible thing to do.=20
=20
VASI, ACUC SP5223=20
"I can resist anything but temptation", O. W., LWf.=20
=20
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From: VASI <sot...@inta.es>=20
Newsgroups: rec.scuba=20
Subject: Re: Q: If I miss my deco-stop?=20
Date: Mon, 14 Oct 1996 16:39:44 -0700=20
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