BSAC tables under fire.
Rolf M. Koksvik
1995.
TAKING A STEP INTO DEEP AND MUDDIED WATERS?
Are lives put at risk by guidelines issued by the British Sub-Aqua
Club? Many divers think so. Simon Rogerson reports.
As the leaders of Britain's biggest scuba diving club meet for their
annual review this weekend a lone voice is threatening to disturb the
waters. At the end of a season already noted for a series of fatal
accidents, a senior instructor has broken ranks to claim current
safety guidelines are putting lives at risk.
Diving instructor John Barnard says that four out of every 10 British
Sub-Aqua Club (BSAC) divers who get the bends have observed
guidelines; and his claim is backed up by recent figures which suggest
that 37-39 per cent of all decompression accidents occur within the
BSAC safety limits.
Barnard was driven to make his stand when he suffered decompression
sickness - the bends - after a 37-metre dive off the north Norfolk
coast. "It was a challenging dive so I followed the safety procedures
fastidiously, but even so I suffered a spinal bend which affected my
leg. The effect was comparable to a stroke."
Barnard, 53, was sent to the recompression chamber at Whipp's Cross
Hospital, north London, and eventually made a full recovery. He was
pronounced fit to dive again but the experience has left him
suspicious of safety tables introduced by the BSAC in 1988.
The tables set out the limits for how long a diver can stay at any
given depth without risking the bends. BSAC divers are taught how to
use the tables in their earliest training sessions and rely on them
for the rest of their diving careers.
Barnard believes, however, that the tables throw caution to the winds
in the most dangerous situations, such as the one he found himself in.
"The problem is that they allow divers to come to the surface more
quickly than did their predecessors - they are putting their lives at
risk and I no longer feel happy teaching them."
Barnard is appealing for other divers who share his concerns to make
themselves known to the BSAC at the Diving Officer's Conference today
and tomorrow at Wembley Conference Centre, when the Accidents and
Incidents Report will be discussed. Up till now many people who
survive the bends have kept quiet about their experiences, fearing for
their reputations as safe or competent divers.
One BSAC insider, who asked not to be named, said the tables have
become a laughing stock among experienced divers. He said many of them
prefer to use wrist mounted computers which are pre-programmed with
tables researched by European and American scuba manufacturers.
"The problem with the '88 tables is that while they are quite
conservative in some respects, they go really close to the edge on
some high-risk dives that require decompression stops. It is
ridiculous because in many ways, the BSAC has one of the best training
systems: British divers are renowned across the world for their
expertise. We dive in some of the most challenging conditions possible
and we need tables to match the environment."
Former BSAC diver Steve Williams switched his allegiance to the rival
club, the Professional Association of Diving Instructors (PADI), when
he decided to become a scuba instructor. His main motive for the
change was to get away from the stigma surrounding the '88 tables.
"I wouldn't be happy teaching those tables to my students," he said.
"They are just too risky on the more dangerous dives. I know quite a
few people who have got the bends after diving within the BSAC limits.
One man who stuck religiously to the tables was driving away from a
dive site when he suffered a neural bend behind the wheel. His body
went numb and he lost control of the car - it was a miracle he didn't
die. He was taken to a recompression chamber really quickly but even
then the doctors told him to stay out of the water for 18 months."
Decades of research have been poured into the development of diving
tables but there are still factors such as weakness, ill-health or
dehydration that can make an otherwise safe diver susceptible to the
bends. All tables have been calculated conservatively to leave
forgiving error margins and take account of uncontrollable but,
according to Williams, some of them are safer than others.
"English divers have enough to contend with in the form of cold, murky
and sometimes dangerous waters they choose to explore." he said.
"There is absolutely no need to make things worse by teaching tables
that increase the danger by pushing the limits of human physiology.
The BSAC should take a long, hard look at the '88 tables."
The BSAC's chairman, Howard Painter, said that no level of injury is
acceptable, but added that with a sport like diving some accidents are
inevitable. "Our tables are the only ones that have been conceived and
produced specifically for sport diving," he said. "The others are
derivatives of US Navy tables with widened safety margins. We don't
recommend decompression diving but we train our students to understand
it so that if they do choose to attempt it, they know what they are
doing."
Painter explained that the old and new BSAC tables cannot really be
compared because they rely on different principles. He said the more
recent tables are safer and more conservative because the ascent time
is incorporated into the total time.
"The '88 tables are probably the least complicated ones because the
diver just has to turn pages - there is no mathematical calculation to
make. Also, they take account of atmospheric pressure changes in their
calculations. But to compare the '88 tables with their predecessors is
just facile because they are based on different concepts.
"It is worth stressing that the preparation of diving tables is not an
exact science. The British Navy initially used pigs to work out the
effects of breathing air at pressure and it was very much a case of
trial and error. We've come a long way since then but the tables can
still be affected by factors like stress or even a heavy drinking
session the night before.
"Divers have to be responsible for themselves and conduct their dives
conservatively if they are getting old or if the conditions are
hostile. As with many sports, the only way to prevent all accidents is
to stop practicing - and we can't have that."
----------------------------------------------------------------------
DRASTIC CUTS IN SAFETY MARGINS
Reconstructing the dive that gave him the bends, John Barnard compared
his depth and time limits with the precautions he would have taken
under the old BSAC tables.
On a single dive to 37 metres with a bottom time of 16 minutes, he
would have carried out safety stops for five minutes at 10 metres and
again at five metres. The stops would have given him precious time to
let nitrogen bleed out of his system and prevent the gas forming
dangerous bubbles in his bloodstream when he surfaced.
But under the 1988 tables, and allowing for a total dive time of 16
minutes including the descent, he was required to carry out only a
one-minute stop at six metres.
"Even acknowledging that the ascent time is part of the stop time with
the old tables, the total bottom-to-surface time - which was crucial
to my safety - is significantly different. There has been a drastic
cut in the safety margin with the most dangerous dives - the ones
which require decompression stops. The laws of nature have not changed
in the past seven years but the safety margins have been reduced by
the BS-AC."
-------
Rolf M. Koksvik, ESA/ESTEC, Noordwijk, The Netherlands
rkok...@vmprofs.estec.esa.nl
J Shepherd
Thank you Rolf; I look forward to hearing from people who
attended the DOC and may have a comment on this.
It's very hard to say what 'reasonable' stops are; as Painter
said, Deco is a very inexact science. The more I read into it the longer
my safety stops get.
It's also true that the 88 tables if understood and taught
properly are used as minimal guidelines before any stress; just as the
Aladin used to be until they started buggering about with it.
Finally, the one fact I was looking for I missed. Was the
protagonist of this article afflicted by PFO or not, and did he discuss
the impact of PFO on DCI prediction? This is something that is being
kept out of the stats, and I want to see it in there.
Personally I feel the moral of these stories is, Diving Is
Dangerous (and the longer you stay and the deeper you go, the more
dangerous it gets).
We aren't out walking the dog.
Jason
Charlie Hammond
In article <95331.0927...@estec.estec.esa.nl>,
>This article appeared in The Daily Telegraph on Saturday, November 25, 1995.
>Are lives put at risk by guidelines issued by the British Sub-Aqua
>Club? Many divers think so. Simon Rogerson reports.
>...the BSAC has one of the best training systems: British divers are renowned
>across the world for their expertise. ...
..
This is not a universal opinion. I have met at least one PADI instructor
who claims that BSAC training is so erratic that he will not accept
BSAC certifications. I suspect this is an over-reaction to an isolated
problem or two, but I also suspect that BSAC is overrated.
..
>The BSAC's chairman, Howard Painter, said ...
>. "Our tables are the only ones that have been conceived and
>produced specifically for sport diving," he said. "The others are
..
Apparently Mr Painter has never heard or the PADI/DSAT Recreational
Dive Planner, the DCIEM Sport Diving tables, or the various Bühlmann
tables. Something is wrong if the BSAC chairman is this ignorant.
..
>diver just has to turn pages - there is no mathematical calculation to
>make. Also, they take account of atmospheric pressure changes in their
..
Personally, I find it deeply insulting to suggest that I can't do simple
addition and multiplication.
Objectively I would argue that some simple math is much more likely to be
done correctly than correctly choosing tables from the thirty-two tables in
the BSAC system. (The other systems use three basic tables plus an
altitude correction table for dives done at altitudes significantly above
sea level.)
I also argue that the use of thirty-two tables and the attemppt to
"take account of atmospheric pressure changes" tends to falsely imply
a greater accuracy than the current knowldege of decompression science
can support. But it actually delivers less precision than both the
aforementioned PADI, DCIEM and Bühlmann tables, and the various tables
derived from the US Navy tables.
------------
note: Bühlmann is often spelled Buehleman in english.
--
Charlie Hammond -- Digital Equipment Corporation -- Nashua NH USA
All opinions expressed are my own and do not necessarily reflect
my employer's position.
Peter J Johnston
>
>In article <95331.0927...@estec.estec.esa.nl>,
>Rolf M. Koksvik <RKOK...@estec.estec.esa.nl> writes:
>
>>Are lives put at risk by guidelines issued by the British Sub-Aqua
>>Club? Many divers think so. Simon Rogerson reports.
>>...the BSAC has one of the best training systems: British divers are renowned
>>across the world for their expertise. ...
>..
> This is not a universal opinion. I have met at least one PADI instructor
> who claims that BSAC training is so erratic that he will not accept
> BSAC certifications. I suspect this is an over-reaction to an isolated
> problem or two, but I also suspect that BSAC is overrated.
>..
>>. "Our tables are the only ones that have been conceived and
>>produced specifically for sport diving," he said. "The others are
>..
> Apparently Mr Painter has never heard or the PADI/DSAT Recreational
> Dive Planner, the DCIEM Sport Diving tables, or the various Bühlmann
> tables. Something is wrong if the BSAC chairman is this ignorant.
>..
>>diver just has to turn pages - there is no mathematical calculation to
>>make. Also, they take account of atmospheric pressure changes in their
>..
> Personally, I find it deeply insulting to suggest that I can't do simple
> addition and multiplication.
>
> Objectively I would argue that some simple math is much more likely to be
> done correctly than correctly choosing tables from the thirty-two tables in
> the BSAC system. (The other systems use three basic tables plus an
> altitude correction table for dives done at altitudes significantly above
> sea level.)
>
> I also argue that the use of thirty-two tables and the attemppt to
> "take account of atmospheric pressure changes" tends to falsely imply
> a greater accuracy than the current knowldege of decompression science
> can support. But it actually delivers less precision than both the
> aforementioned PADI, DCIEM and Bühlmann tables, and the various tables
> derived from the US Navy tables.
Hey Charlie, are you trying to fan the kindling and get the old PADI-BSAC
"mine is better than yours" flame war going ;)...oh well I'll bite....
Who gives a toss what one disgruntled diver thought of BSAC tables, in
addition does anyone ever really believe what either the press or the head
of an organisation says.......big pinches of salt all round I think.
The only table that will guarantee a 100% no-bend dive is the one you are
sitting at at the moment. All tables have inherant risks...you go deeper
longer and you will increase the risk. Even dive computers do not make
those risks magically disappear (although I am sure Cochran enterprises
will soon be producing one incorporating a "dialysis" system that defizzes
your blood for you ;)) they take into account the varying depths you have
been at rather than calculate purely square profile dives. I use tables as
a backup for my computer...they will almost always be more conservative.
As for the complexity of various brands of table, it does not matter as
long as you know how to use them, none of them are exactly rocket science
are they?. Besides, as far as I can tell the BSAC tables are similar to
most others except they tend to USE BIGGER LETTERS and separate out the
individual surface codes. They also go deeper and have more deco-dive
information hence more table-space (plus of course increased risks of DCS).
It will be interesting to hear what the breakdown of this years horrendous
tally of incidents will produce. We shall have to wait for an attendee at
the DOC to comment (how about a transcript of the incident report sheet,
that always makes good reading). My bet is that the rate of compression
fatality will be outbid by drownings due to other factors (DV freezes, OOA
etc) but we shall have to wait and see. Of course no bend is a good bend
(except a U-bend ;)) but I doubt whether the rate of DCS has been
significantly increased by the BSAC 88s.....then again as I said who gives
a toss.
Woops I forgot Charlie incited a war.........PADI sucks.......a friend of
a friend's great aunt three times removed told me he had met some really
bad PADI divers.....so it must be true.
Pete (and his asbestos dry suit)
Dillon Pyron
Okay, I see the number "four out of ten" and "37-39 per cent" of decompression
accidents. But, what per centage of total dives is this? And how many of these
dives that were "within the limits" really were? Two of the six diver I
personally know who have been bent were certain they were inside the tables, even
though one had a computer screaming violation at him and the other had an MDI
showing 15 ft deeper than he claimed to be at.
And no table will be 100% safe. You'll still die if you do life at 0 ft.
dillon
Pete Young
> This article appeared in The Daily Telegraph on Saturday, November 25,
> 1995.
Must be true then, eh? After all, we all believe everything we read
in the press with the possible exceptions of Sunday Sport and Diver.
Thanks to Rolf for spotting it: we were all too busy at DOC to read the
papers!
> Diving instructor John Barnard says that four out of every 10 British
> Sub-Aqua Club (BSAC) divers who get the bends have observed
> guidelines; and his claim is backed up by recent figures which suggest
> that 37-39 per cent of all decompression accidents occur within the
> BSAC safety limits.
Mmm. I have in front of me the BSAC NDC Incidents report for 1995.
The MOST recent figures show that between 18 and 20% of incidents in
1994/ 1995 were within limits, a 50% reduction from last years figure
(which appears to be what the Telegraph was using).
Interestingly this is matched by a 100% increase (ie from 20% of all
incidents in 1994 to 39% in 1995) in the number of incidents involving
rapid ascents. Tim Parish, the BSAC Diving Incidents advisor was in
no doubt that this change was a result of improved information on which
to base the analysis.
> Barnard believes, however, that the tables throw caution to the winds
> in the most dangerous situations, such as the one he found himself in.
> "The problem is that they allow divers to come to the surface more
> quickly than did their predecessors - they are putting their lives at
> risk and I no longer feel happy teaching them."
Emotive stuff. I'm glad to hear he recovered, but as we all know there
are many factors which we can only guess at from this report. For
instance, did he ascend at the correct rate? Did he observe the 1 minute
to ascend from 6m? Was there any evidence of PFO? Given that the diver
was 53 years old, shouldn't he have considered building in a bit more
safety? Was repeat diving involved? And so on.
I think there IS a problem with divers assuming that if you do what the
table says, you will not get bent. It doesn't require great leaps of
imagination to build in some extra margin for error, and what's the
hurry to get back to the surface? No tables guarantee that you will not
get bent. That said ...
> "The problem with the '88 tables is that while they are quite
> conservative in some respects, they go really close to the edge on
> some high-risk dives that require decompression stops.
I believe this to be true, and I am prepared to state quite clearly that
I am not impressed with BSAC 88 and much prefer the SAA Buelhmann
tables.
In particular I would not use BSAC-88 for decompression diving. However,
for the majority of diving, which is no-stop diving above 30, the
BSAC-88 tables are at least as conservative as US Navy and derivatives
such as PADI.
But you don't have to take my word for it: read the excellent chapter
in Deeper Into Diving, by Dr. John Lippman. He expresses similar
opinions based on a far greater knowledge of the facts.
[A PADI Instructor said]
> "I wouldn't be happy teaching those tables to my students," he said.
> "They are just too risky on the more dangerous dives.
One hopes that Mr Williams is not teaching risky decompression dives to
his current students!
> Reconstructing the dive that gave him the bends, John Barnard compared
> his depth and time limits with the precautions he would have taken
> under the old BSAC tables.
Is he seriously suggesting that BSAC should go back to using RNPL
tables? I think not. It does appear that RNPL are more conservative for
certain profiles but having studied the manuals last night in most
cases BSAC-88 is more conservative. Perhaps some of the crusties who can
remember using RNPL would care to comment on this?
> But under the 1988 tables, and allowing for a total dive time of 16
> minutes including the descent, he was required to carry out only a
> one-minute stop at six metres.
My Buelhmann tables give a 4-minute stop at 3m for a 37m dive of 15
minutes. This is comparable given that the 16 minutes on BSAC-88
includes an ascent time of 2 minutes from 37m to 6m. This is more
conservative than BSAC-88, but less conservative than RNPL.
Oh well. With the onset of Nitrox, BSAC had a glorious opportunity to
ditch BSAC-88 tables and espouse the use of Buelhmann. So what did they
do?
You guessed it: BSAC is now preparing it's own Nitrox tables for 32 and
36% mixtures, based on BSAC-88 and it's brain-dead way of handling
residual nitrogen (hence no equivalent air depth for repeated dives).
At this point I should probably say that, despite my position as Branch
DO of 2030 branch, these words reflect my opinions only and have nothing
to do with BSAC or anyone else.
--
____________________________________________________________________
Pete Young pyo...@srd.bt.co.uk Phone +44 1473 640885
"Just another crouton, floating on the bouillabaisse of life"
Charlie Hammond
RE: Pete (and his asbestos dry suit)
^^^^^^^^^^^^^^^^^
Hey, where can I get on of these????
But seriously, folks, it was NOT my intent "to fan the kindling and get the old
.. flame war going". From everything that I can see and hear, BSAC is as fine
an organization as PADI, even if they both tend to overstate their own
importance from time to time. We could say the same about SAA, NAUI, SSI, NSDS,
PDIC, YMCA and any just about all others too, I suppose.
BUT, I do think that when such a representative as Howard Painter, BSAC
chairman, makes such a totally ingorant statement as "Our tables are the only
ones .... for sport diving", then he should be called to account.
The reading that I have done suggest that in fact the BSAC tables are not
as well researched and tested as the PADI/DSAT RDP, the DCIEM tables, or the
Buehlmann tables.
Peter J Johnston
>
>RE: Pete (and his asbestos dry suit)
> ^^^^^^^^^^^^^^^^^
> Hey, where can I get on of these????
>
Sorry, I am still working on the patent........
>But seriously, folks, it was NOT my intent "to fan the kindling and get the old
>.. flame war going". From everything that I can see and hear, BSAC is as fine
>an organization as PADI, even if they both tend to overstate their own
>importance from time to time. We could say the same about SAA, NAUI, SSI, NSDS,
>PDIC, YMCA and any just about all others too, I suppose.
>
>BUT, I do think that when such a representative as Howard Painter, BSAC
>chairman, makes such a totally ingorant statement as "Our tables are the only
>ones .... for sport diving", then he should be called to account.
Absolutely, unfortunatly, as usual, we have to judge his statements via
the press....(hey Howard get a modem so we can "chat")...and we all know
how such statements can be placed out of context. But I am not going to
defend either the tables or the BSAC chairman. As far as I am concerned no
table is to trusted 100%, they should all be used as "guidelines" and then
a hefty safety margin thrown on top. As for statements by commitee
members...well that is just politics.
Pete
steve foster
>
>In article <95331.0927...@estec.estec.esa.nl>,
>Rolf M. Koksvik <RKOK...@estec.estec.esa.nl> writes:
>>...the BSAC has one of the best training systems: British divers are renowned
>>across the world for their expertise. ...
>..
> This is not a universal opinion. I have met at least one PADI instructor
> who claims that BSAC training is so erratic that he will not accept
> BSAC certifications.I suspect this is an over-reaction to an isolated
> problem or two, but I also suspect that BSAC is overrated.
Do you mean you have met ONE PADI instructor who believes this? Or did a PADI
instructor share his experience of "an isolated problem or two" with a whole bunch
of 'em before reaching their decision and then disseminating their sanctimonious
clap-trap? I think we should be told...
I think you're on thin ice, but this, probably, "is not a universal opinion".
No, I don't think BSAC is better than PADI, I just think BSAC is a good system,
for me, who dives in Britain. I've been a novice with both agencies, but then what
do people like me know - I'm not even in the
rec.scuba-bandwidth-hogging-armed-response-unit.
>>"The '88 tables are probably the least complicated ones because the
>>diver just has to turn pages - there is no mathematical calculation to
>>make. Also, they take account of atmospheric pressure changes in their
>>calculations. ...
>..
> Personally, I find it deeply insulting to suggest that I can't do simple
> addition and multiplication.
Noone's saying Charlie Hammond can't do simple addition and multiplication, what
Mr. Painter is saying is that Charlie Hammond, along with every other Tom, Dick
and Harry makes simple mistakes from time to time. Or perhaps not, perhaps just
Tom et.al?
> Objectively I would argue that some simple math is much more likely to be
> done correctly than correctly choosing tables from the thirty-two tables in
> the BSAC system.
I'm sorry Charlie, that was the WRONG answer, you only look at about FOUR tables
on an average day's diving with the BSAC system.
I've used both PADI and BSAC tables extensively, BSAC tables are easier to use. To
a large extent they can be committed to memory for common dive profiles.
Perhaps you would like to post something debating the safety of the BSAC deco
requirements, which is the nature of the original posting, instead of starting a
PADI Vs BSAC zzzzz, zzzzzzz, zzzzzzzz, zzzzzzzzzz, (whoops, sorry, just fell
asleep there) slanging match, which is about as clever as pissing in the wind.
Don't tell me, you and your PADI instructor mates can piss further than BSAC
divers, right?
Steve.
Carl Heinzl
This post is *not from me* - I was asked to post it by Jason Shepherd
(j...@festival.ed.ac.uk)... If anyone attributes anything said here,
you'll be flamed until toasted brown :^)
ham...@star.enet.dec.com (Charlie Hammond) writes:
>RE: Pete (and his asbestos dry suit)
> ^^^^^^^^^^^^^^^^^
> Hey, where can I get on of these????
>But seriously, folks, it was NOT my intent "to fan the kindling and get the old
>.. flame war going". From everything that I can see and hear, BSAC is as fine
>an organization as PADI, even if they both tend to overstate their own
>importance from time to time. We could say the same about SAA, NAUI, SSI, NSDS,
>PDIC, YMCA and any just about all others too, I suppose.
>BUT, I do think that when such a representative as Howard Painter, BSAC
>chairman, makes such a totally ingorant statement as "Our tables are the only
>ones .... for sport diving", then he should be called to account.
>The reading that I have done suggest that in fact the BSAC tables are not
>as well researched and tested as the PADI/DSAT RDP, the DCIEM tables, or the
>Buehlmann tables.
>--
> Charlie Hammond -- Digital Equipment Corporation -- Nashua NH USA
>
> All opinions expressed are my own and do not necessarily reflect
> my employer's position.
Says he quoting almost verbatim from Lippman, who was writing in
1989, a year after the tables are dated!
If people are unhappy with a deco management system, there must
be a reason...
i) they got bent using it. Bummer - contrary to the papers, most
'within table' bends, weren't. There will be a hit rate inside the
tables, this is the nature of life, gentlemen. Wake up.
ii) They were brought up on a different set of stats. This is a
*very* powerful force in opinion; I know that I myself compare
everything to the 88s, as they were the first system I used. To my mind
therefore, computers like the old Aladin were liberal bubble monsters,
especially on repetative dives; the RNPL tables were risky, the PADI
wheel looks a nightmare to use, etc.
There is *no* reason for somebody to start declaring risk levels
on these different systems unless they are powerfully well qualified.
You just don't *know* if the 88s are significantly riskier than any
other system. You may feel it, but you don't know.
iii) they know something we don't. There are always odd facts
about a system which have difficulty surfacing; how many 88 users have
read *all* the little fudge rules at the beginning of the table, or are
aware that the risk level is *designed* to go up below 35m because stops
to the same risk level as NS<35m dives are prohibitively long? Who knows
those expected hit rates *are*?
Or with computers, how many people are aware of the gaps between
the models and observed stats on deep or repetative dives? Or the one
about repeat deco chasing on your coral reef holiday? Or take the full
manual with them wherever they go, or plan a full dive profile before
hopping in? I know *you* do (or at least none of you will say otherwise)
but many folks don't, which is why computers have such a bad reputation,
particularly with chamber operators.
This means therefore that people qualified to pontificate on
deco management systems are i) open minded (probably by being exposed to
so many systems over such a long time that they could rewrite lippman
and make a decent book out of it) ii) either never bent, or bent under
all systems and iii) very very well read.
In other words the kind of people asked by a worldwide diving
agency to design a set of easily available deco mangement rules.
(As opposed to those designing computers for money ;-) ).
The stats on 88 usage are good. The problems are bad dive
conduct and low skill levels.
And for the protagonist of the article, it is recommended that
divers getting on in years add a tissue code, or depth band, or time
slot, to add conservatism. Like the writers of Tunnels and Trolls said;
you've bought it, it's yours, do what you like with it.
You plan your deco; not BSAC, or PADI, or DECOM or anyone else.
Jason
Pete Plocher
DECO table (computerized or other) is that generally they are theoretical
and based on a model which is not well understood - the human tissue model.
Pete Plocher
J Shepherd
Geee, Carl, does that mean you disagree? (Flyfishing for another
flamefest cos I'm booooored). :-)
Thanks, anyway, you're a gem, sir.
Jason
Carl Heinzl
Jason,
> Geee, Carl, does that mean you disagree? (Flyfishing for another
>flamefest cos I'm booooored). :-)
Nope - I didn't even read it - I had too much to do but I wanted to
get it out quick as I could...
Now that I have read it I still must feign ignorance. I am not
familiar with the BSAC tables or their little rules that must be
followed and could not contribute to a discussion about it.
I do know that I would NOT use tables whose risk is designed to go up
below 35m... But, I take personal responsibility for my diving...
Sorry, Jason - no flamefest here :^)
-Carl-
Charlie Hammond
In article <49na79$m...@oban.cc.ic.ac.uk>,
steve foster <s.fo...@ic.ac.uk> writes:
>I've used both PADI and BSAC tables extensively, BSAC tables are easier to use.
That is your opinion. Although I've no extensive experience with the BSAC
tables I do have a set and I believe that I could use them without great
difficulty. Nevertheless, my expereince leads me to believe that users
of the BSAC tables would be likely to make mistakes by selecting the wrong
table, either figuring it wrong or simply looking at the wrong page.
So my opinion differs. No big deal....
>To a large extent they can be committed to memory for common dive profiles.
This is true of every dive table I have ever seen, heard of, or can
imagine. I would opinion that PADI/DCIEM/Buehlmann type table are
eaier to memorize, but I'd bet you'd disagree. Again, no big deal...
>Perhaps you would like to post something debating the safety of the BSAC deco
>requirements, which is the nature of the original posting, instead of starting
..
Whoa up there, fella! I may be guilty of taking the bait -- alright, I
AM guilty -- but it was the head of the BSAC who was originally quoted
as making the objectively false statement that the BSAC tables are the
only ones designed and tested sport diving. That was the statement that
I refused to let stand without correction. Unless he was miss-quoted
or taken extremely out of context, that statement is way, way, way off.
Stephen Archer
>This article appeared in The Daily Telegraph on Saturday, November 25,
>1995.
>
>TAKING A STEP INTO DEEP AND MUDDIED WATERS?
>
>Are lives put at risk by guidelines issued by the British Sub-Aqua
>Club? Many divers think so. Simon Rogerson reports.
>
>
>Diving instructor John Barnard says that four out of every 10 British
>Sub-Aqua Club (BSAC) divers who get the bends have observed
>guidelines; and his claim is backed up by recent figures which suggest
>that 37-39 per cent of all decompression accidents occur within the
>BSAC safety limits.
>
>Barnard was driven to make his stand when he suffered decompression
>sickness - the bends - after a 37-metre dive off the north Norfolk
snip
>
>Barnard, 53, was sent to the recompression chamber at Whipp's Cross
snip
>"The problem with the '88 tables is that while they are quite
>conservative in some respects, they go really close to the edge on
>some high-risk dives that require decompression stops. It is
>ridiculous because in many ways, the BSAC has one of the best training
>systems: British divers are renowned across the world for their
>expertise. We dive in some of the most challenging conditions possible
>and we need tables to match the environment."
>
snip
>
>Reconstructing the dive that gave him the bends, John Barnard compared
>his depth and time limits with the precautions he would have taken
>under the old BSAC tables.
>
>On a single dive to 37 metres with a bottom time of 16 minutes, he
>would have carried out safety stops for five minutes at 10 metres and
>again at five metres. The stops would have given him precious time to
>let nitrogen bleed out of his system and prevent the gas forming
>dangerous bubbles in his bloodstream when he surfaced.
>
>But under the 1988 tables, and allowing for a total dive time of 16
>minutes including the descent, he was required to carry out only a
>one-minute stop at six metres.
>
snip
>
>-------
>Rolf M. Koksvik, ESA/ESTEC, Noordwijk, The Netherlands
>rkok...@vmprofs.estec.esa.nl
Not arguing for or against the tables - I no longer use them!.
But we need more info before we can fully judge this! Using the old tables
if this chap hadn't dived for 6 hours then it would have been treated as
a first dive!!
The article appears to claim he only did a non-deco dive.
The photos that accompanied this article showed him with his standard set up
-- twin 12L (~104cuft) cylinders
Also what was he diving at this depth??
I ask because it's very similar to a friends bend. Again deep diving - repeative
but one dive a day for 3 or 4 days at a time - all first dives. Diving to 50M to
recover the Bell telegraph and compass
Much of this required stenuous work
Oh yes and he was 52 years old!
Looking back my mate thought he'd probably asked for it.
Stephen//Stephen
e-mail: sarche...@rx.xerox.com
BSAC Advanced Diver
St. Albans Sub-Aqua club. Cotton Mill Lane, St. Albans, England
Club nights Wednesday + Friday 7:30 til 11:00
Iain Robertson
>The photos that accompanied this article showed him with his standard set up
>
>-- twin 12L (~104cuft) cylinders
>
Not so, actually. The photo was taken (I think) at a local
quarry, with the PADI instructor (not the guy who got bent) in
the water.
The set you can see in the picture is being worn by one of the
instrucotr's students, and was borrowed from the owner of the
shop the instructor works for. The tanks, BTW are 7l, not 12.
--
Iain Robertson London England <rober...@oldpeter.agw.bt.co.uk>
John Grogan
'c...@zurich.ai.mit.edu (Carl Heinzl)' wrote:
>>BUT, I do think that when such a representative as Howard Painter, BSAC
>>chairman, makes such a totally ingorant statement as "Our tables are the
only
>
>>ones .... for sport diving", then he should be called to account.
>
that started this whole debate and I was at the Diving Officers Conference
in November where Howard addressed the audience on this issue.
Howards statement was that the BS-AC 88 tables were the only tables that
were developed from scratch for sport diving - NOT that they were the only
ones for sport diving. By his statement, he meant that the BS-AC quite
literally started from basics in developing these. Many other
organisations use tables based on the US Navy tables or Buhlmann tables or
some other derivative. To my knowledge no other sport diving organisation
has completely developed their own tables - however, I stand open to
correction.
--
John Grogan
BS-AC Advanced Diver, Putney Branch Diving Officer
J Shepherd
>On 1 Dec 95 in article <Re: BSAC tables under fire.>,
>'c...@zurich.ai.mit.edu (Carl Heinzl)' wrote:
>
>
>
>>>BUT, I do think that when such a representative as Howard Painter, BSAC
>>>chairman, makes such a totally ingorant statement as "Our tables are the
>only
>>
>>>ones .... for sport diving", then he should be called to account.
>>
>
>I think some clarification is needed here. I read the newspaper article
>that started this whole debate and I was at the Diving Officers Conference
>in November where Howard addressed the audience on this issue.
>
>Howards statement was that the BS-AC 88 tables were the only tables that
>were developed from scratch for sport diving - NOT that they were the only
>ones for sport diving. By his statement, he meant that the BS-AC quite
>literally started from basics in developing these. Many other
>organisations use tables based on the US Navy tables or Buhlmann tables or
>some other derivative. To my knowledge no other sport diving organisation
>has completely developed their own tables - however, I stand open to
>correction.
>--
>
>John Grogan
>
>BS-AC Advanced Diver, Putney Branch Diving Officer
>
>
>
>
I believe you are correct; and here's another factlet to throw
into the pot. The guy complaining about the 88's claimed to be concerned
because the old RNPL tables would have given him 5@10 and 5@5 or
somesuch.
The RNPL tables as used by sports divers were *severly* fudged;
all stops were rounded up to the nearest five minutes, and any dive
below a certain depth (25m?) had a stop at 10m.
Applying those fudge rules to the 3@6 he claimed the 88s gave
him and we see where the RNPL tables come from.
The idea behind decompression tables is they give you basic
information to work with; they don't even claim to prevent decompression
sickness. I got really irritated by this case. If the guy wants to
complain about something, he ought to pick on the teaching of
decompression worldwide, which is minimal in most situations. It's not
good enough to say that some people just can't understand this, we need
to be teaching better.
Sounds like this may have been a case in point, but if this
gentleman got the impression that BSAC 88 tables would prevent DCI and
that at his advanced age he should be carrying out deep diving without
extra conservation, someone somewhere missed a bit out.
All IMHO, of course...
(Hoping that I gave NT5, ST6 and ST7 well enough this year)
Jason
Charlie Hammond
I believe that the following quote came from me:
>>BUT, I do think that when such a representative as Howard Painter, BSAC
>>chairman, makes such a totally ingorant statement as "Our tables are the
>>only ones .... for sport diving", then he should be called to account.
Now we're being told that:
>Howards statement was that the BS-AC 88 tables were the only tables that
>were developed from scratch for sport diving - NOT that they were the only
>ones for sport diving. ...
Well, this statement is incorrect. The PADI/DSAT Recreational Dive Planner
was developed from scratch for sport diving, not derived from US Navy or
other tables. It is also my understanding that the DCIEM sports diving
tables and the Buehlmann tables were also developed independently and
specificcally for sports diving.
>By his statement, he meant that the BS-AC quite
>literally started from basics in developing these. Many other
>organisations use tables based on the US Navy tables or Buhlmann tables or
>some other derivative.
Is it good to ignore this history of theoretical research and practicaly
experience?
J Shepherd
>I believe that the following quote came from me:
>>>BUT, I do think that when such a representative as Howard Painter, BSAC
>>>chairman, makes such a totally ingorant statement as "Our tables are the
>>>only ones .... for sport diving", then he should be called to account.
>Now we're being told that:
>>Howards statement was that the BS-AC 88 tables were the only tables that
>>were developed from scratch for sport diving - NOT that they were the only
>>ones for sport diving. ...
>Well, this statement is incorrect. The PADI/DSAT Recreational Dive Planner
>was developed from scratch for sport diving, not derived from US Navy or
>other tables. It is also my understanding that the DCIEM sports diving
>tables and the Buehlmann tables were also developed independently and
>specificcally for sports diving.
>>By his statement, he meant that the BS-AC quite
>>literally started from basics in developing these. Many other
>>organisations use tables based on the US Navy tables or Buhlmann tables or
>>some other derivative.
>Is it good to ignore this history of theoretical research and practicaly
>experience?
>--
> Charlie Hammond -- Digital Equipment Corporation -- Nashua NH USA
>
> All opinions expressed are my own and do not necessarily reflect
> my employer's position.
I think this could get bitter, and it's a bit pointless.
i) Everyone I ask here confirms Mr Painter's statement. Nearly
all other tables are derived from the US Navy Tables, or relatives. The
BSAC 88's went straight to the data (all that was available anyway, and
BSAC do have one of the biggest independant DCI databases in the world)
for the first time in a long while.
To discredit this view, get quotes from higher sources, or do
what I'm going to do, ignore the issue, it's pointless.
ii) Mr Painter is one of relatively few people in UK diving who
has a public relations role to play wrt a particular agency. We do
indulge in our fair share of agency (usually PADI) bashing; it's fun and
mind expanding, but *he* has an elected position to fill and is in a
relatively difficult position. If he is *wrong* therefore, forget it. If
he's right, forget it as well... Address the tables issue.
I can see that a number of people feel insulted by what he has
said. I doubt very much indeed that he would have said it if he didn't
believe it himself to be true. But how are we going to argue about such
pointless issue. The problem is people getting bent, not PR advice being
right or wrong.
Heniway,
Ahm off.
Jason
Hyperbaric Operations
> >... It is also my understanding that the DCIEM sports diving
> >specificcally for sports diving.
Just for your information, DCIEM Diving Tables were developed specifically
for the Canadian Armed Forces between 1983 and 1986. Since then a number
of foreign navies and commercial diving companies have adopted these
tables for their own use. DCIEM Sports Diving Tables, based on the above
mentioned tables were originally published in 1988 and subsequently have
been redesigned to allow for altitude and multi-level diving. DCIEM Sports
Diving Tables are now in use around the world by many recreational diving
agencies.
Martin Necpal, CHT
DCIEM
Charlie Hammond
In article <4b48at$m...@scotsman.ed.ac.uk>,
j...@festival.ed.ac.uk (J Shepherd) writes:
> I think this could get bitter, and it's a bit pointless.
>
> i) Everyone I ask here confirms Mr Painter's statement. Nearly
>all other tables are derived from the US Navy Tables, or relatives. ...
Not to put too fine a point on it, but if you defend Mr Painter by changing
what he said from "ONLY" to "NEARLY", then, yes, it may well get bitter
and is certainly pointless.
The man miss-spoke. Period. OK, we all do that sometimes. Forget it.
Continuing to defend an obvious miss-statement (or, if you prefere, one taken
out of context) quickly becomes silly.
You can get info on the PADI/DSAT RDP from either PADI or DSAT. You can find
information on the RDP, DCIEM, BUEHLMAN, BSAC and other tables in "Deeper Into
Diving" by John Lippman.
When you say "Everyone I ask here", who is "everyone" and where is "here"?
J Shepherd
>In article <4b48at$m...@scotsman.ed.ac.uk>,
>j...@festival.ed.ac.uk (J Shepherd) writes:
>> I think this could get bitter, and it's a bit pointless.
>>
>> i) Everyone I ask here confirms Mr Painter's statement. Nearly
>>all other tables are derived from the US Navy Tables, or relatives. ...
>Not to put too fine a point on it, but if you defend Mr Painter by changing
>what he said from "ONLY" to "NEARLY", then, yes, it may well get bitter
>and is certainly pointless.
I am not defending Mr Painter, I am trying to stop people
wasting their time by attacking him. He is very unlikely to appear here
to defend himself and most of us have given up on what he said.
>The man miss-spoke. Period. OK, we all do that sometimes. Forget it.
>Continuing to defend an obvious miss-statement (or, if you prefere, one taken
>out of context) quickly becomes silly.
Yup. So does attacking it...
>You can get info on the PADI/DSAT RDP from either PADI or DSAT. You can find
>information on the RDP, DCIEM, BUEHLMAN, BSAC and other tables in "Deeper Into
>Diving" by John Lippman.
I have been through Lippman once or twice, and wasn't that
impressed; it didn't go very deep. He is also rather out of date (unless
it's been updated since '89). And since some of what he writes is
incorrect... (BSAC 88 tables were based on data going way back - sport
diving data not pushing it miloitary data, and had been in use
approximately a year when he became very critical of them. When I see
writing like that I wonder... hmmm. Does he know Tom Hennessey? Do they
get on?). Anyway.
>When you say "Everyone I ask here", who is "everyone" and where is "here"?
BSAC regional coaches, industrial people, advanced instructors
(*not* the same as PADI advanced) etc. People who really ought to know
something. No I don't trust a word they tell me, but then I don't trust
a word you, or anybody else tells me. I don't think this issue (was Mr
Painter accurate or not) is going to kill me, so I'm not going to bother
reading up on it.
Why has this got you so pissed?
>--
> Charlie Hammond -- Digital Equipment Corporation -- Nashua NH USA
>
> All opinions expressed are my own and do not necessarily reflect
> my employer's position.
Jason.
Ob interest... Pissed in the UK means drunk. I hope it still
means 'annoyed' in the US.
John Grogan
'ham...@star.enet.dec.com (Charlie Hammond)' wrote:
>Now we're being told that:
>
>>Howards statement was that the BS-AC 88 tables were the only tables that
>>were developed from scratch for sport diving - NOT that they were the
only
>>ones for sport diving. ...
>
>Well, this statement is incorrect. The PADI/DSAT Recreational Dive
Planner
>was developed from scratch for sport diving, not derived from US Navy or
>specificcally for sports diving.
>
developed specifically for sport diving.
>>By his statement, he meant that the BS-AC quite
>>literally started from basics in developing these. Many other
>>organisations use tables based on the US Navy tables or Buhlmann tables
or
>>some other derivative.
>
>Is it good to ignore this history of theoretical research and practicaly
>experience?
ignored.