How conserve air when necessary

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In a hypothetical situation because of some problem such as entanglement you find yourself getting low on air without a buddy are there any techniques one can use to make your air last longer?

Would skip breathing help?

I'm looking for fact based answers other than the obvious (stay calm, move slowly, etc.).
none that will make any difference...

your gas is limited. your ability to stretch your gas is even more limited. if it was easy to stretch gas to any significant extent, then nobody would be asking for al100's instead of al80's.

as with many posts along these lines, the best counsel is to avoid the situation by having proper training, gear and following proper procedures. this is a situation that is easily avoided.
 
"keep in mind, the urge to breath is not driven by lack of oxygen, but build up of CO2" Thank you eelnora.

Exactly. That is where I was going. I've been diving for 48 years, am a solo diver, always dive with a pony and never been entangled but wanting to improve my knowledge. Freedivers can go for 4 minutes on a single breath so just wondering how to maximize my time if anything happens that requires me to be under longer than planned.

Exhaling perfectly good oxygen before necessary seems a waste if you find yourself needing to conserve air. That was the reason for my question.

Regards,

Bert
 
"keep in mind, the urge to breath is not driven by lack of oxygen, but build up of CO2" Thank you eelnora.

Exactly. That is where I was going. I've been diving for 48 years, am a solo diver, always dive with a pony and never been entangled but wanting to improve my knowledge. Freedivers can go for 4 minutes on a single breath so just wondering how to maximize my time if anything happens that requires me to be under longer than planned.

Exhaling perfectly good oxygen before necessary seems a waste if you find yourself needing to conserve air. That was the reason for my question.

Regards,

Bert

Bert, holding your breathe would conserve gas. When diving at depth, the body has more than enough oxygen in the tissues (because of the increased partial pressure) to survive without breathing for an extended period of time. The potential problem with breathe holding at depth is, as others have mentioned, the build up of CO2. CO2 is 130 times more narcotic than nitrogen. The added narcotic effect of the CO2 would most likely impair your ability to remove yourself from the entanglement. Personally, if I became entangled, I would stop everything and concentrate on remaining calm and slowing my breathing. I would then try to remove the entanglement in a calm and relaxed manner so as not to increase your heart rate (breathing). I would prefer to be out of gas once out of the entanglement and perform a controlled emergency swimming ascent than hold my breathe trying to remove the entanglement.
 
I wouldn't call it skip bresthing, but you CAN intentionally slow your breathing and your heart rate considerably. Call it biofeedback or call it Zen, both require some practice and sometimes a mentor to get you started.
Though I wouldn't be bothered to learn this, I think this sort of thing is what the OP is asking about (rather than all the advice--including by me-- about how to avoid entanglement and procedures for escaping, which I'm sure most of us know--or should know).
 
"CO2 is 130 times more narcotic than nitrogen." That's exactly the information that I'm looking for - thank you crookshanky! A good scientific reason not to hold your breath to conserve air. I've experienced the effect of narcosis and didn't even know I was narked until doing a dexterity test. I am guessing that the narcotic effect of CO2 is also depth dependent.
 
Though I wouldn't be bothered to learn this, I think this sort of thing is what the OP is asking about.

if you want to learn about the yogic breathing processes, prepare to take a trip down to hippy town and get your fill of pseudoscience and snake oil. google the various terms and there are multiple instructional videos. yoga studios sometimes will offer dedicated mediation/breathing classes or groups. there's lots of good benefits to meditation and breathing exercises, but if you listen to some people you'd think it'll cure cancer, grow back hair on a bald head, and give you superpowers. i digress...

the overall practice of breath control falls under 'Pranayama'. There are three main practice types, and all are subsets of applied meditation.

'Ujjayi Pranayama'; where the glottis is held slightly open like when you say 'ha' and the mind is focused on the breath and heart. breath is through the nose, full inhales and exhales, with a brief pause between. primarily used during vinyasa yoga practice, with a count of 3~5 seconds per breath. when seated, breath count ranges from 15 to 60+ seconds depending on experience. I find this to be the most useful to practice in regard to SCUBA, as a closed glottis is not a good thing, and increasing lung capacity allows for wider buoyancy control.

'Nadi Shodhana Pranayama', 'alternate nose breathing'; glottis remains slightly open and breath is still through the nose, but each nostril is blocked off in sequence: block left, inhale, exhale, unblock left, block right, inhale, exhale, repeat. again, meditative practice and slowing of the breath, heart, and mind is the process. 10~30 seconds per breath.

'Kapalabhati Pranayama', 'skull shining breath' (seriously); fast, forceful breaths from the belly, about twice a second. used between intervals of Nadi Shodhana and Ujjayi. repeat 25~100x, then return to resting Ujjayi. think of it as high intensity interval training for your lungs and brain. you go from a 'resting' state, to max effort without straining for a minute, then back to 'resting'.

all three of the breathing practices are to be done without straining. attempting to use a 30 second breath cycle on active SCUBA is a good way to retain a bunch of CO2, but being able to mindfully bring your breathing rate down from a panic response is a key skill. stop, breathe properly, think, act.
 
A couple more thoughts to add.

Free diving there is a 'storing up' of oxygen and flushing co2 followed by the breath hold. Immediately after surfacing another recovery period is needed. Breathing off a tank I find breath holding reduces my overall dive time significantly.

Mild skip breathing and calming techniques can stretch a bottle though... Calm is key, slowed heart rate etc.

Nothing else I've come across helps significantly.

Regards,
Cameron
 
I like lap swimming at local Jr. College pool and also a local city pool (free 6-7:30am. Just leave donation for Lifeguards). I practice trying to reduce the number of strokes it takes me to get across the pool. I also sometimes get into a rhythm to swim across with the least amount of breaths. Not feeling like I need to breath or actually holding my breath. Just slow exhale over time and a nice deep inhale when I need to breath. I normally do sets of 500yd for each and about 1-1.5mi total.

I am lazy and should get my heart rate up 3 or more times a week for more than 20 min., but unless I am swimming with someone of the same speed or have a coach yelling out the swim set, I just cruise.
 
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You might want to consider diaphragmatic breathing. I'm a long time sax player, and practiced this for years before taking up diving. As a fairly new diver, even on my first few dives, my SAC rate was around .5 cfm and lately down to .40 - .45 when things are normal. I actually had a minor equipment issue that caused me to expend a lot of energy and gas the first five minutes of my last dive, but then put myself into "supercalm zen mode" to make up for it, and still came up near last in the group, so it can be used in a planed way to conserve gas.. That is, once you get diaphragm control, you can consciously manage your breathing much easier. I normally don't have to think about it, but if I have to i can reduce my gas consumption a bit more than normal by being more conscious about my breathing. And I keep the notion of "small bubbles" in my head as well.

The diaphragm is a muscle and needs to be exercised to keep it in shape and working efficiently. The exercises are straightforward, and I would advise anyone who dives to work on them. Here is one of many sources

Diaphragmatic Breathing Exercises & Techniques | Cleveland Clinic
 
...I am guessing that the narcotic effect of CO2 is also depth dependent.

That is correct Bert. Similar to nitrogen, the deeper you go, the higher the partial pressure and the greater the narcotic effect. That is why CO2 is a potential hazard for deep technical dives. Simple tasks at extreme depths can cause CO2 to build up and quickly incapacitate a diver.
 
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