Saturation
Medical Moderator
Bren, what gases was this diver diving?
A Minor (TRUE) Horror Story
- Thread starter Bren Tierney
- Start date
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OP
Bren Tierney
Contributor
Sorry 'Lucid',
I've no idea who you are and wasn't aware I was bringing anyone into the fray other than those who felt the need/desire to comment.
I've asked Peter to come here himself and answer your questions and comment about the dive in question. I've just received a PM from 'Gozumm' asking me which gases Peter was using on the dive in question. The answer is good old '21%' Air.
Hopefully Peter should be along shortly to get in amongst this debate.
Regards and dive safe,
chris_b
Contributor
Bren, I think it was a joke. You wrote a subject line that said something about "lucid responses," and Lucid responded :bonk:
peter k
Guest
Hello, I am the diver that this topic is all about and Bren told me to join in to at least defend myself. I'll tell you a bit about me first though. I have been diving with ScotSAC(Scottish Sub-Aqua Club) for nearly three years and have done 220-230 dives. Most of my dives have been between 30-40mtrs(100-130ft). They have all been in Scotland and a substantial chunk have been to the wrecks in Oban, Clyde, Moray Firth + others. So I may not be the most experienced in the world, but I'm not a 10 dives a year holiday diver either.
In answer to some of the queries above
I realise they seem a bit over the place but I'm answering as I scroll down and come across a question or something I disagree with)
(1) I was using a borrowed Aladin Sport a my usual 'pooter is broken diving off air.
(2) My computer deco on dive 1 was 8mins at 3mtrs and my no-stop time on dive 2 was still 5mins away. I am not a complete idiot as the guy above seems to think because, whether he believes it or not, I know how to read a computer.
(3) What the Buhllmans would have told me is 2mins@9, 4mins@6 and 12mins@3. This is based on 39mtrs with a bottom time of 25mins. I would have came out with a G and the next dive would have been a B(11min penalty). Dive number 2 is off the Buhllman tables. Alas, I wasn't using Buhllmans(future note to self).
(4) My buddy actually did 2mins less deco than me on dive 1 and we both did a safety stop of about 3mins on dive 2.
(5) All Hyperbaric units are not found in hospitals. Most of Scotlands are in marine lab units to comply with HSE diving at work regulations.
(6) These two dives are dives I have done on the same day in this order a few times before.
And to finish off, as a reflection of Mr mole:
Definately a duff diver. NO computer on the market would have allowed these dives, even an Oceanic!!!!!!!
"I'm afraid you are very wrong there. The times in my original posts were total dive times. RTFP"
Even without a computer my brain knew that the first dive was going to need about 40 mins of stops and the second 30 mins or so. Dont you plan your dives before you do them!!
"Your brain was obviously calculating deco and not reading."
As for the pot attendant, Both DAN's and BSAC incident figures show that Deco rates per diver per dive are roughly the same now as they were in the 70's before computers come about, despite more deeper diving being done.
"His reason for this is people tend to push themselves closer to the limit with computers than if they were following a strict pre-dive planned table"
Bloke is obviously a Darwin Award candidate in serious need of more dive training .
"At least I'm a candidate for something, you certainly wouldn't be a candidate for your 11+ in reading. If you've nothing constructive to say, then don't say it."
Peter
In answer to some of the queries above
I realise they seem a bit over the place but I'm answering as I scroll down and come across a question or something I disagree with)(1) I was using a borrowed Aladin Sport a my usual 'pooter is broken diving off air.
(2) My computer deco on dive 1 was 8mins at 3mtrs and my no-stop time on dive 2 was still 5mins away. I am not a complete idiot as the guy above seems to think because, whether he believes it or not, I know how to read a computer.
(3) What the Buhllmans would have told me is 2mins@9, 4mins@6 and 12mins@3. This is based on 39mtrs with a bottom time of 25mins. I would have came out with a G and the next dive would have been a B(11min penalty). Dive number 2 is off the Buhllman tables. Alas, I wasn't using Buhllmans(future note to self).
(4) My buddy actually did 2mins less deco than me on dive 1 and we both did a safety stop of about 3mins on dive 2.
(5) All Hyperbaric units are not found in hospitals. Most of Scotlands are in marine lab units to comply with HSE diving at work regulations.
(6) These two dives are dives I have done on the same day in this order a few times before.
And to finish off, as a reflection of Mr mole:
Definately a duff diver. NO computer on the market would have allowed these dives, even an Oceanic!!!!!!!
"I'm afraid you are very wrong there. The times in my original posts were total dive times. RTFP"
Even without a computer my brain knew that the first dive was going to need about 40 mins of stops and the second 30 mins or so. Dont you plan your dives before you do them!!
"Your brain was obviously calculating deco and not reading."
As for the pot attendant, Both DAN's and BSAC incident figures show that Deco rates per diver per dive are roughly the same now as they were in the 70's before computers come about, despite more deeper diving being done.
"His reason for this is people tend to push themselves closer to the limit with computers than if they were following a strict pre-dive planned table"
Bloke is obviously a Darwin Award candidate in serious need of more dive training .
"At least I'm a candidate for something, you certainly wouldn't be a candidate for your 11+ in reading. If you've nothing constructive to say, then don't say it."
Peter
GearHead
Contributor
Here's my take:
Diver has a personal story about DCS that is posted so that board may learning from his misfortune.
Scubaboard members rip into him for the mistakes he knows he's made, perhaps making themselves feel superior for a moment or two.
Shameful.
Thanks for posting more details about your experience, Peter. It takes someone with a pair of big brass ones to share an awful episode like that, and any diver reading this thread should be grateful for the opportunity to learn instead of kicking you while you're down. I commend you for contributing to the board.
Diver has a personal story about DCS that is posted so that board may learning from his misfortune.
Scubaboard members rip into him for the mistakes he knows he's made, perhaps making themselves feel superior for a moment or two.
Shameful.
Thanks for posting more details about your experience, Peter. It takes someone with a pair of big brass ones to share an awful episode like that, and any diver reading this thread should be grateful for the opportunity to learn instead of kicking you while you're down. I commend you for contributing to the board.
Alladin Sport is a 9 or 6 (cant remember) tissue BUHLMANN model computer with extra fudge factors. It should always give slightly longer deco than pure Buhlmann. (I own one!! long retired), so I cant see how it gave less deco than pure tables, unless it is faulty. The only way to get the deco down this low would have been to do a quick bounce to the bottom and then get up shallow very quickly. Having said that its algorythm is considered very lenient by todays standards
If you've done that dive many times before with the same deco, then you're a very very lucky man, I certainly wont be doing that on air, and I would't use a Buhlmann model either
Both you and your partner are VERY lucky to have got away with this (and previous) dives. I stand by my comments, You need MORE training in decompression and you need to plan your dives in advance, not just swim around until the computer says so as you have discovered. If you cant accept that you screwed up on this dive and need to change your procedures and planning, then give up diving now or you will end up in the pot again
If you run these dives through ProPlanner, GAP, DDPlan, DPlan, VPlanner, ZPlanner, BSAC 88, Buhlmann, RDP, DCIEM etc etc you will see that you need a LOT more decompression (most suggest around 30 - 40 mins worth on the first dive alone). Proplanner was the least conservative with 28 mins of stops starting at 23m (Assuming Square profile 37m for 25mins).
By the way I can read, and 45mins TDT - 8mins deco - 4 mins Ascent does not = the 25 mins BT you used in your last post, it = 32 mins, quite a difference especially on deco
I have every sympathy for people who get bent due to no fault of their own, following planned dives. But to omit 20 mins of stops, relying on a single borrowed computer during an unplanned dive???? and then blame the computer!
How was your buddy calculating his deco by the way? what did his computer and or tables say? why didn't you follow them? and why did he do 2 mins less deco than you, A buddy pair should do the same deco, not split up in the water
I'm sorry, but wake up and smell the roses before its too late, you screwed up big time through your own ignorance and bad diving practices (I'm certain SCOTSAC teach you how to plan and calculate deco). You cant deny this as the evidence is slightly stacked against you. Dont bother with excuses, learn something from this!!! PLAN THE DIVE, DIVE THE PLAN and never ever rely on a single device
If you really really really still believe you did nothing wrong and that you didn't break the deco rules then I'd suggest you get tested for a PFO
Feel free to flame away if it makes you feel better, I have a thick drysuit and thick skin underneath. I havn't yet managed to get a bend in nearly 3000 dives down to 140m (touch wood) so I must be doing something sorta right
Computers and tables use the same algorythms underneath or similar variations of these algorythm's, Pushing either to the limits is bad. Pushing beyond these limits almost always gets you in the pot!!! as you now know. Both deco calculation methods are only as good as the people using them
This is not intended as a flame post and I dont want to start a war. I just want you to learn something from your experiance and download some deco programs, learn how to use them and run your dives through them before you do them, That way you have a mental sanity check of what a computer is telling you and can plan your gas and bailout requirement in advance. Also take at least 2 ways of measuring depth and dive time with you on every dive (and cross check them)
(NOT SAYING THIS APPLIES TO YOU, but its kind of related)
I work in a dive shop accasionally and the amount of folks we get in who cant use their computers properly is frightning, I had one guy just before Xmas convinced his TDT display was his NST, When we downloaded his profiles from his recent red sea trip, He'd been to 68m on air and missed 32 mins of stops on his last dive!!! (and got away with it!!!!). Claims as he wasn't deco trained, he couldn't do deco and therefore could ignore the deco stop stuff on the computer!!!!!!!!! If only life was a simple as this guy
If you've done that dive many times before with the same deco, then you're a very very lucky man, I certainly wont be doing that on air, and I would't use a Buhlmann model either
Both you and your partner are VERY lucky to have got away with this (and previous) dives. I stand by my comments, You need MORE training in decompression and you need to plan your dives in advance, not just swim around until the computer says so as you have discovered. If you cant accept that you screwed up on this dive and need to change your procedures and planning, then give up diving now or you will end up in the pot again
If you run these dives through ProPlanner, GAP, DDPlan, DPlan, VPlanner, ZPlanner, BSAC 88, Buhlmann, RDP, DCIEM etc etc you will see that you need a LOT more decompression (most suggest around 30 - 40 mins worth on the first dive alone). Proplanner was the least conservative with 28 mins of stops starting at 23m (Assuming Square profile 37m for 25mins).
By the way I can read, and 45mins TDT - 8mins deco - 4 mins Ascent does not = the 25 mins BT you used in your last post, it = 32 mins, quite a difference especially on deco
I have every sympathy for people who get bent due to no fault of their own, following planned dives. But to omit 20 mins of stops, relying on a single borrowed computer during an unplanned dive???? and then blame the computer!
How was your buddy calculating his deco by the way? what did his computer and or tables say? why didn't you follow them? and why did he do 2 mins less deco than you, A buddy pair should do the same deco, not split up in the water
I'm sorry, but wake up and smell the roses before its too late, you screwed up big time through your own ignorance and bad diving practices (I'm certain SCOTSAC teach you how to plan and calculate deco). You cant deny this as the evidence is slightly stacked against you. Dont bother with excuses, learn something from this!!! PLAN THE DIVE, DIVE THE PLAN and never ever rely on a single device
If you really really really still believe you did nothing wrong and that you didn't break the deco rules then I'd suggest you get tested for a PFO
Feel free to flame away if it makes you feel better, I have a thick drysuit and thick skin underneath. I havn't yet managed to get a bend in nearly 3000 dives down to 140m (touch wood) so I must be doing something sorta right
Computers and tables use the same algorythms underneath or similar variations of these algorythm's, Pushing either to the limits is bad. Pushing beyond these limits almost always gets you in the pot!!! as you now know. Both deco calculation methods are only as good as the people using them
This is not intended as a flame post and I dont want to start a war. I just want you to learn something from your experiance and download some deco programs, learn how to use them and run your dives through them before you do them, That way you have a mental sanity check of what a computer is telling you and can plan your gas and bailout requirement in advance. Also take at least 2 ways of measuring depth and dive time with you on every dive (and cross check them)
(NOT SAYING THIS APPLIES TO YOU, but its kind of related)
I work in a dive shop accasionally and the amount of folks we get in who cant use their computers properly is frightning, I had one guy just before Xmas convinced his TDT display was his NST, When we downloaded his profiles from his recent red sea trip, He'd been to 68m on air and missed 32 mins of stops on his last dive!!! (and got away with it!!!!). Claims as he wasn't deco trained, he couldn't do deco and therefore could ignore the deco stop stuff on the computer!!!!!!!!! If only life was a simple as this guy
tinman
Contributor
...quite right! Certainly a lot of stones being thrown by sinners and the virtuous alike. Peter, my Mother was born in Paisley, Scotland so you and I both know that Scots can endure suffering - perhaps that was why Scotch Whiskey was invented! We also share a penchant for cold water. There are many lessons to be learned here and I commend your frankness and willingness to allow us all to share in that journey of discovery. My best wishes for a complete recovery...
The Iceni
Medical Moderator
Hi Peter,
As a lowly punter can I welcome you aboard. I hope your post was not your last on Scubaboard as I find it very informative. Unlike certain fora in the UK, this forum tends to be much more educational and gentlemanly and very few posts could be described as agressive, let alone abusive. Flaming is a very, very rare and fround-upon commodity here. (and of course reflects badly on the poster, not his victim.)
Oops. yes indeed the Dunstaffnage pot is one I know of that is not in a "hospital". I was trying to emphasise the point that in the UK at least Diver injuries should be taken to a chamber not to the A&E of a district general hospital.
I hope you did not take my other comments wrongly. I have very good reasons to support the buddy system as two heads are better than one, and in my opinion my own let me down badly. In your case also, the buddy system appears to have failed.
I am very concerned about the amount of denial you (both) clearly suffered which Dr Deco confirms is almost a constant feature of DCI, and by no means a " failing" on your part. Perhaps this should be like the adage used by doctors. Every fertile female is preganant until proven otherwise. Perhaps every symptom suffered by a diver is DCI until proven otherwise!
Any chance of seeing your profiles?
I really am very glad you recovered. Like me you are very lucky.
Kind regards and safe diving!
As a lowly punter can I welcome you aboard. I hope your post was not your last on Scubaboard as I find it very informative. Unlike certain fora in the UK, this forum tends to be much more educational and gentlemanly and very few posts could be described as agressive, let alone abusive. Flaming is a very, very rare and fround-upon commodity here. (and of course reflects badly on the poster, not his victim.)
Oops. yes indeed the Dunstaffnage pot is one I know of that is not in a "hospital". I was trying to emphasise the point that in the UK at least Diver injuries should be taken to a chamber not to the A&E of a district general hospital.
I hope you did not take my other comments wrongly. I have very good reasons to support the buddy system as two heads are better than one, and in my opinion my own let me down badly. In your case also, the buddy system appears to have failed.
I am very concerned about the amount of denial you (both) clearly suffered which Dr Deco confirms is almost a constant feature of DCI, and by no means a " failing" on your part. Perhaps this should be like the adage used by doctors. Every fertile female is preganant until proven otherwise. Perhaps every symptom suffered by a diver is DCI until proven otherwise!
That sounds pretty experienced to me in such a short time. In consequnce, sadly, I think you ought to have been routinely planning your dives a little better.
Any chance of seeing your profiles?
I really am very glad you recovered. Like me you are very lucky.
Kind regards and safe diving!
Saturation
Medical Moderator
Thanks Bren.
Planned decompression dives are best done with technical level training and equipment. It makes the higher risks more manageable.
Best wishes,
Marv
Planned decompression dives are best done with technical level training and equipment. It makes the higher risks more manageable.
Best wishes,
Marv
Dr Deco
Contributor
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Dear Peter and Readers:
No Decompression
As many of you will have noted during the couple of years that I have been writing these replies, I have stated that there are not any No-Decompression Limits that apply to all divers. Problems can increase with an increase in gas loads. The tables and meters all have a large degree of latitude in them, especially if strenuous activity is avoided. Naturally this means that if you miss some decompression, probably nothing will happen. Can you even miss a lot of decompression? Some can, such as the black coral divers in Hawaii. Many of these are also paralyzed learning that they were not resistant divers.
Quid, me vexo? [What, me worry?]
I say this missed decompression stuff with trepidation always fearing that someone will actually plan dives that are out of the ballpark. Can you sometimes get away with it? These fellows say they did several times. But, as they say, When it works, it works well, but when it fails, it fails catastrophically. This can kill you .
We have not talked about this in this forum (it is discussed in the Decompression Physiology class), but you CANNOT increase the tissue gas dose to increase the bends problem. You reach a point (with animals) where they die; some never display symptoms of the bends.:boom:
Many Thanks
This is a wonderful illustration of gas loads. Sometimes you can get away with some big loads. (The fellows in The Last Dive did not.) Big loads and long walks are really pushing it, but you say you have done this before, and I believe it. I certainly would not try it again. That you lived shows that God was in a good mood that day!
Dr Deco :doctor:
No Decompression
As many of you will have noted during the couple of years that I have been writing these replies, I have stated that there are not any No-Decompression Limits that apply to all divers. Problems can increase with an increase in gas loads. The tables and meters all have a large degree of latitude in them, especially if strenuous activity is avoided. Naturally this means that if you miss some decompression, probably nothing will happen. Can you even miss a lot of decompression? Some can, such as the black coral divers in Hawaii. Many of these are also paralyzed learning that they were not resistant divers.
Quid, me vexo? [What, me worry?]
I say this missed decompression stuff with trepidation always fearing that someone will actually plan dives that are out of the ballpark. Can you sometimes get away with it? These fellows say they did several times. But, as they say, When it works, it works well, but when it fails, it fails catastrophically. This can kill you .
We have not talked about this in this forum (it is discussed in the Decompression Physiology class), but you CANNOT increase the tissue gas dose to increase the bends problem. You reach a point (with animals) where they die; some never display symptoms of the bends.:boom:
Many Thanks
This is a wonderful illustration of gas loads. Sometimes you can get away with some big loads. (The fellows in The Last Dive did not.) Big loads and long walks are really pushing it, but you say you have done this before, and I believe it. I certainly would not try it again. That you lived shows that God was in a good mood that day!
Dr Deco :doctor:
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