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Static breathhold while scuba diving
- Thread starter wdaf
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 90 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
interesting things i found.
CO2 Retention
CO2 Acclimatization
last one with the interesting freediving fact:
The term "shallow water blackout" was used in 1944 by Barlow and MacIntosh (9) for blackout suspected, and later confirmed, from too high CO2 levels (hypercapnia). It was termed "shallow water" because oxygen rebreathers could not be used in deep water because of the high oxygen content. Most of the cases weren't deep enough to have been O2 toxicity, which had previously been the prime suspect. The problem subsided after improving carbon dioxide absorption canisters. Although the term "shallow water blackout" had the established meaning of CO2 retention-induced blackout, it was later applied to unconsciousness from too low oxygen (hypoxia) in breath-hold diving, especially following excessive hyperventilation.
CO2 Retention
CO2 Acclimatization
last one with the interesting freediving fact:
The term "shallow water blackout" was used in 1944 by Barlow and MacIntosh (9) for blackout suspected, and later confirmed, from too high CO2 levels (hypercapnia). It was termed "shallow water" because oxygen rebreathers could not be used in deep water because of the high oxygen content. Most of the cases weren't deep enough to have been O2 toxicity, which had previously been the prime suspect. The problem subsided after improving carbon dioxide absorption canisters. Although the term "shallow water blackout" had the established meaning of CO2 retention-induced blackout, it was later applied to unconsciousness from too low oxygen (hypoxia) in breath-hold diving, especially following excessive hyperventilation.
did you or the others who have that opinion ever try spearing fish bigger than 20kg on scuba?
well, freediving i shoot them and let the bungee/float do a lot of the work.
some scuba guys go rodeo with the fish. not bored!
for sure thats not safe at all. but they are informed - they dont have a problem with their personality (loved that quick explanation) - they know the risks and they have had accidents.
i have to add that this diving is not in a western society + i dont recommend or advertise for that kind of diving and safety thinking.
it is extreme but since i am a foreigner in this country it is non of my business to use my western rules and norms to judge them or expain them what to do.
Trux already covered the important facts. The dangers of breath holding on SCUBA have to do with barotrauma risk, and issues/complication associated with having increased CO2 levels in the body. It is always recommended to avoid breath-holding while on SCUBA. This is the easy and safe way to teach because it maintains the greatest margin to thresholds that may be dangerous. More importantly, the SCUBA student does not need to know about all of the detailed physiology that can create an unacceptable level of risk on a dive to implement this simplified technique.
In reality, these dangers associated with breath-holding while on SCUBA can be managed by other means. This subject is similar to the old teaching of never dive beyond 130 ft. It can be done, but to do it safely requires knowledge and skills that the typical diver may not have. It is also important to recognize that even when you think you know what you are doing when it comes to CO2 retention issues, you will absolutely be closer to a dangerous situation than you would be with continuous breathing. That said, by managing appropriate depth and levels of physical exertion, breath-holding on SCUBA can be accomplished without a catastrophic outcome. The fact that your students have been doing this without injury is evidence to this.
The real probem here is that there are no established methods for managing these risks during a dive. The research has note been done like it has been done for decompression and deep diving. So, the message you want your students to have is that when they are doing this, in addition to getting close to a fish by not making noisy bubbles, they are also making themselves a test subject in an unmonitored diving physiology experiment with unknown levels of risk. Ultimately, it is up to the diver to determine whether the risks of their actions are worth it to them in any given situation.
Ron
In reality, these dangers associated with breath-holding while on SCUBA can be managed by other means. This subject is similar to the old teaching of never dive beyond 130 ft. It can be done, but to do it safely requires knowledge and skills that the typical diver may not have. It is also important to recognize that even when you think you know what you are doing when it comes to CO2 retention issues, you will absolutely be closer to a dangerous situation than you would be with continuous breathing. That said, by managing appropriate depth and levels of physical exertion, breath-holding on SCUBA can be accomplished without a catastrophic outcome. The fact that your students have been doing this without injury is evidence to this.
The real probem here is that there are no established methods for managing these risks during a dive. The research has note been done like it has been done for decompression and deep diving. So, the message you want your students to have is that when they are doing this, in addition to getting close to a fish by not making noisy bubbles, they are also making themselves a test subject in an unmonitored diving physiology experiment with unknown levels of risk. Ultimately, it is up to the diver to determine whether the risks of their actions are worth it to them in any given situation.
Ron
In a pole conducted by Diver magazine a year or so ago , just over 50% of the respondents said they held their breath on scuba .
Here's a few of the comments :-
" I do this without really thinking , to control buoyancy . "
" Everyone skip-breathes , even if it's just to get bouyancy right for a good photo . "
" Show me a photograther who doesn't and they either take crap pictures or tell lies . "
" Only when at constant depth , and then not all the time . "
There were an equal number of comments from divers who don't skip-breathe .
So from this survey at least , you can say around 50% of divers hold their breath in some way or other and some of the reasons why .
As has been pointed out by others , the potential dangers include carbon dioxide retention and burst lung .
I used to skip-breathe to save air but it does give you the mother of all head aches , much better is to relax to the point of catatonia , breathe in slowly and out even slower without holding the breath , no head ache and a tank lasts longer than with skip-breathing .
There are however , times when I do hold my breath , for fine-tuning bouyancy control or to not frighten the wildlife . I understand the dangers and except beginers must be discouraged from breath-holding but for me it's a useful and sometimes necessary technique .
Regards ,
Dave .
Here's a few of the comments :-
" I do this without really thinking , to control buoyancy . "
" Everyone skip-breathes , even if it's just to get bouyancy right for a good photo . "
" Show me a photograther who doesn't and they either take crap pictures or tell lies . "
" Only when at constant depth , and then not all the time . "
There were an equal number of comments from divers who don't skip-breathe .
So from this survey at least , you can say around 50% of divers hold their breath in some way or other and some of the reasons why .
As has been pointed out by others , the potential dangers include carbon dioxide retention and burst lung .
I used to skip-breathe to save air but it does give you the mother of all head aches , much better is to relax to the point of catatonia , breathe in slowly and out even slower without holding the breath , no head ache and a tank lasts longer than with skip-breathing .
There are however , times when I do hold my breath , for fine-tuning bouyancy control or to not frighten the wildlife . I understand the dangers and except beginers must be discouraged from breath-holding but for me it's a useful and sometimes necessary technique .
Regards ,
Dave .
Nice answer Ron.
Outside of our perfect little 'in theory' bubble and while we are discussing physiology this and deco that remember we are dealing with real life too.
If they do have an incident who will bail them out of the proverbial?
If its each other risking their own lives lifting a tonic phase diver up from 50m to their own boat, driving them to their own reco chamber for treatment fair play to them.
If not, just ask them if I'm ever on holiday to take a week off so the resources I might need as a prudent diver aren't all taken up. A&E is full of loads of people saying I didn't think that would happen alongside the genuinely unlucky.
Faaannnkksss
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Outside of our perfect little 'in theory' bubble and while we are discussing physiology this and deco that remember we are dealing with real life too.
If they do have an incident who will bail them out of the proverbial?
If its each other risking their own lives lifting a tonic phase diver up from 50m to their own boat, driving them to their own reco chamber for treatment fair play to them.
If not, just ask them if I'm ever on holiday to take a week off so the resources I might need as a prudent diver aren't all taken up. A&E is full of loads of people saying I didn't think that would happen alongside the genuinely unlucky.
Faaannnkksss
Posted via Mobile Device
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There are some really unlucky people around as well as the gun-ho
1998 Urban Legend: Scuba Divers and Forest Fires
Posted via Mobile Device
1998 Urban Legend: Scuba Divers and Forest Fires
Posted via Mobile Device
There are some really unlucky people around as well as the gun-ho
1998 Urban Legend: Scuba Divers and Forest Fires
Posted via Mobile Device
Poor bugger what a horrible way to go!
Apneaboy pointed out something I missed .
wdaf was asking about holding the breath for up to two minutes .
If you stay at a constant depth burst lung is not an issue , but they must be close to the onset of co2 toxicity .
Symtoms include :-
nausea
vomiting
dizziness
head ache
rapid breathing
rapid heart rate
flushing
confusion
convulsions
loss of consciousness .
None of which sound like good things to have under water .
Maybe ask these guys if they ever get the beginings of these symptoms , at least they'd know that they're pushing it too far , if they say they're fine then you can't tell people what to do , only advise them of the dangers .
So despite what may have come across in my other post , I'd like to say holding your breath on scuba for two minutes is probably a very bad idea .
Regards ,
Dave .
wdaf was asking about holding the breath for up to two minutes .
If you stay at a constant depth burst lung is not an issue , but they must be close to the onset of co2 toxicity .
Symtoms include :-
nausea
vomiting
dizziness
head ache
rapid breathing
rapid heart rate
flushing
confusion
convulsions
loss of consciousness .
None of which sound like good things to have under water .
Maybe ask these guys if they ever get the beginings of these symptoms , at least they'd know that they're pushing it too far , if they say they're fine then you can't tell people what to do , only advise them of the dangers .
So despite what may have come across in my other post , I'd like to say holding your breath on scuba for two minutes is probably a very bad idea .
Regards ,
Dave .
here's and interesting quote on "Skip breathing"
it is from this free diving medical book called "Edmunds diving medicine" i will dig out the link and post it later
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Scuba, never hold your breath underwater
Freediving, never breath underwater
Save you trawling all those threads
Deeperblue at its best
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THX Revan, Dave!
very good answeres.
these divers realize its their own responsibility and an extreme sport with high risks if you go for the big fishes.
so the risk is part of the game. who joins their trips acknowledges that.
i was involved in accidents, and nobody sewed or accused somebody afterwards.
very good answeres.
these divers realize its their own responsibility and an extreme sport with high risks if you go for the big fishes.
so the risk is part of the game. who joins their trips acknowledges that.
i was involved in accidents, and nobody sewed or accused somebody afterwards.
One thing is taking a calculated risk that you are aware of, and another thing is going into a risky situation without being even aware it is risky, just because of lack of information. I may be wrong, but from your initial posts, I am under the impression you and your friends were not completely aware of the risks. Otherwise you would probably not ask what the risks are. So it is definitely good decision to study the topic closer. Once you are aware of the effects, you can better evaluate whether your actions are worth of the increased risk, and you can take additional safety precautions (for example having oxygen for faster degassing ready, cutting the bottom-time, increasing deco-stops, and slowing down the ascend, ...). Ventilating well after the breath-hold would be good for removing the excess CO2, but in the same time you could black out already just by doing it - it is hyperventilation. Besides it the fast changes of CO2 level in both directions have similar effects to rapid descents and ascents, so it may not be the best idea to hyperventilate on scuba either.
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good tips:
thx trux.
yes, my friends and myself we are not completely aware of the risks. that's why i ask here, and i got some good infos.
I wanna try to put all infos together in the next days.
Since i don't wanna encourage others - holding their breath while scuba -what do you think is the right way of doing that?
Something like ...
"If you really wanna risk your life holding your breath during scuba at least read/follow these recommondations" with a big "Own responsibilit ..." at the beginning.
?
@trux:
- O2 or Nitrox deco, slow ascend, longer stopps, smaller bottom time
is clear, but more important to me:
what would be your "recommondation/ideas/do's and dont's" regarding breathing/breathhold pattern?
- maximum breathhold time of absolut value
- like 2 minutes?
- or better a relative value
- 25% of your regular PB?
- or maybe even make it relative to the depth?
- 2 minutes 0-20m
- 1:30 20-40m
- less than 1 minute 40+
- not more than 1 breathhold during 10 minutes?
- no hyperventilation before and afterwards?
- no skip breathing before the actual breathhold?
- as soon as first signs of high CO2 arise STOP?
additional safety infos that could be given:
- no solodiving
- clear emergency procedures
I am afraid there are so many factors involved, that nobody will give you any specific answer. I doubt there are any studies which would tell you how to adjust your deco times, etc - it is already difficult and uncertain enough with plain scuba diving, so if you mix it with apnea, where people react diametrically differently, it is practically impossible. At some persons, the breath-hold may have by magnitude different effects than at others.
However 2 minutes seem already damn long. Average freediving spearos stay underwater usually around one minute. OK, with scuba it is easier since you have higher PaO2, but it is therefore also more risky - you produce more CO2.
My advice would be, if you do not want to spear on freediving, use a rebreather, and breath normally. It makes no bubbles, hence the breathing makes much less noise.
However 2 minutes seem already damn long. Average freediving spearos stay underwater usually around one minute. OK, with scuba it is easier since you have higher PaO2, but it is therefore also more risky - you produce more CO2.
My advice would be, if you do not want to spear on freediving, use a rebreather, and breath normally. It makes no bubbles, hence the breathing makes much less noise.
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I’ll recommend you advise them to keep detailed logs of what they are doing and submit the data to DAN along with dive computer downloads. DAN keeps records of dive accidents and statistics and the information gathered may ultimately end up in a future generation of dive computer algorithms which monitor and compensate for such things. I know it’s a long shot, but maybe it could be useful some day.
If nothing else, it might really drive home the message that they are experimenting in uncharted territory. The idea of keeping the log may seem like too much work which may simply discourage the risky behavior; also, not a bad outcome for the situation.
Ron
If nothing else, it might really drive home the message that they are experimenting in uncharted territory. The idea of keeping the log may seem like too much work which may simply discourage the risky behavior; also, not a bad outcome for the situation.
Ron
If you really wanna risk your life holding your breath during scuba at least read/follow these recommondations YOUR OWN RESPONSIBILIY
DONT DO IT, too many risks and too many things to go wrong.
read this especially the bits about DCS, O2 toxicity and drowning
Edmonds? DIVING MEDICINE
DONT DO IT, too many risks and too many things to go wrong.
read this especially the bits about DCS, O2 toxicity and drowning
Edmonds? DIVING MEDICINE
thx a lot for the book tip!
always good to have a dive medicine book in PDF on the laptop!
the following part was interesting for the breathholding while scuba discussion:
"A rapid accumulation of CO2 may cause unconsciousness before any symptoms are experienced.
A slower build-up causes a variety of symptoms, including :
• shortness of breath, or air hunger.
• flushing of the face and sweating (sweating is not easy to detect underwater).
• repetitive activity, such as swimming, without awareness of this.
• light headedness, muscular twitching, jerks, tremors or convulsions.
• impaired vision.
• unconsciousness.
• a splitting or throbbing headache, usually at the front of the head. This may be severe and start after the CO2 levels have been corrected. It often lasts for hours.
• death.
CO2 toxicity may increase the likelihood of decompression sickness, oxygen toxicity, nitrogen narcosis and resistance to breathing (because of increased respiration). As with oxygen toxicity, there is sometimes an “off effect” whereby the symptoms of CO2 toxicity are temporarily worsened when a diver suddenly resumes breathing normal gases after partially adapting to a high CO2 pressure"
breathholding casues a relatively rapid accumulation of CO2 i guess?
it would be interesting to know how the level of CO2 buildup one gets by a single breathhold is compared to the level of a CO2 retainers (skip breathing during the whole scuba dive)
in case the levels from a single short breathhold dont rise too much, one finding could be that as long as one doesnt do skip breathing during his dive he limits the risks during a single short breathhold.
does that make sense? what do you think?
always good to have a dive medicine book in PDF on the laptop!
the following part was interesting for the breathholding while scuba discussion:
"A rapid accumulation of CO2 may cause unconsciousness before any symptoms are experienced.
A slower build-up causes a variety of symptoms, including :
• shortness of breath, or air hunger.
• flushing of the face and sweating (sweating is not easy to detect underwater).
• repetitive activity, such as swimming, without awareness of this.
• light headedness, muscular twitching, jerks, tremors or convulsions.
• impaired vision.
• unconsciousness.
• a splitting or throbbing headache, usually at the front of the head. This may be severe and start after the CO2 levels have been corrected. It often lasts for hours.
• death.
CO2 toxicity may increase the likelihood of decompression sickness, oxygen toxicity, nitrogen narcosis and resistance to breathing (because of increased respiration). As with oxygen toxicity, there is sometimes an “off effect” whereby the symptoms of CO2 toxicity are temporarily worsened when a diver suddenly resumes breathing normal gases after partially adapting to a high CO2 pressure"
breathholding casues a relatively rapid accumulation of CO2 i guess?
it would be interesting to know how the level of CO2 buildup one gets by a single breathhold is compared to the level of a CO2 retainers (skip breathing during the whole scuba dive)
in case the levels from a single short breathhold dont rise too much, one finding could be that as long as one doesnt do skip breathing during his dive he limits the risks during a single short breathhold.
does that make sense? what do you think?