How Much Air?

[crosshairs]

I know a 30 second exhale might seem amazing to a lot of divers (yourself included, apparently) but it's a de-facto requirement for certification with PADI.

seriously?

This is certainly news to me.

 

[TMHeimer]

Maybe he is referring to CESA, but lung air expands during that, plus I don't believe it has to be from as deep as 30' (which at a foot a second=30 secs.).

 

[boulderjohn]

The PADI confined water CESA requirement is for 30 feet, not 30 seconds. People may quibble that a "normal" ascent is 60 FPM, meaning the 30 feet = 30 seconds, but when I did my IE, the instructor examiner stressed that it was 30 FEET, not 30 seconds, and quicker than 30 seconds was perfectly OK.

More importantly, exhaling while ascending during a CESA is entirely different from exhaling on a normal breath while diving, so this is really not an issue to be considered here.

 

[Joneill]

seriously?

This is certainly news to me.

It's news to everyone (and I'm a newbie)! Scary that this is from a PADI Pro teaching students with this poor understanding?

 

[Patoux01]

I know a 30 second exhale might seem amazing to a lot of divers (yourself included, apparently) but it's a de-facto requirement for certification with PADI.

Please show us the part in the S&P that says this.

 

[Skulmoski]

Consider reading Simon Pridmore's "Scuba Confidential: An Insider's Guide to Becoming a Better Diver". He addresses concerns like this and has helped me to methodically think about and improve my diving (including breathing).

Regards

Greg

 

[Neilwood]

Thank you all. Yes, I do have busy brain. Clearly, I need to work on my breathing topside. Also, lose some lead and swim more efficiently. Not all that easy to work on this an accrue more dives as we live in Chicago. So, there's the quarry....

I would not worry about it. I have noticed that, even in my very limited experience, that your air consumption will change dramatically as you get more comfortable underwater.

Example (all similar profile dives to about 10-12m with no currents to speak off and same gear ie wetsuit, tank, fins mask etc):
OW check out dives - 12l tank @230(ish) bar =approx 30-35 mins.

Few weekends later on a trip with exactly the same gear as above and same tanks
Dive 5 - 12l tank@ 230 bar =35 mins (was actually a deeper profile to about 18-19m)
Dive 6 - 12l tank @230 bar =45 mins
Dive 7 - 12l tank @240 bar =25 mins (no end of issues before the dive so was stressed getting in the water and took about 5-10 mins to completely relax)
Dive 8 - 12l tank @230 bar = 40 mins

So from just getting over 30 mins from a tank I went up to 40-45 mins (bearing in mind the deeper depth of the fifth dive would up my gas usage.

Only differences between dives - how relaxed I was. Dives 1-4 (OW) were stressful due to exam conditions and doing skills, dive 7 was stressful due to equipment issues whereas dives 5,6 &8 were easy going dives with no stress.

Sounds daft but concentrate of being relaxed and smooth instead of worrying.

 

[dmaziuk]

seriously?

This is certainly news to me.

According to pikiwedia it's called bradypnea, it is accompanied by

• Dizziness
• Near-fainting or fainting
• Fatigue
• Weakness
• Chest pains
• Shortness of breath
• Memory impairment or confusion
• Tiring easily during any physical activity

and is caused by

• Degeneration of heart tissue because of aging
• Damage to tissues in the heart from heart attack or heart disease
• High blood pressure or hypertension
• Congenital heart defect which is disorder present at birth
• Heart tissue infection also known as myocarditis -Complication of heart surgery
• Hypothyroidism or underactive thyroid gland
• Imbalance of electrolytes which are mineral related substances needed for conducting electrical impulses
• Obstructive sleep apnea which is the repeated disruption of breathing during sleep.
• Inflammatory disease, such as lupus or rheumatic fever
• Buildup of iron in the organs known as hemochromatosis
• Medications, such as drugs for other heart rhythm disorders, psychosis as well as high blood pressure and narcotic pain medications may also reduce respiratory rate.

HTH, HAND

 

[MXGratefulDiver]

I know a 30 second exhale might seem amazing to a lot of divers (yourself included, apparently) but it's a de-facto requirement for certification with PADI. All of my OW students do this effortlessly, after a bit of practice.

That can't possibly be right ... a trained opera singer might be able to control their exhale for 30 seconds, but most normal human beings would have difficulty doing so for more than about half that, absent the expanding air on a CESA. And even then, a 30-second exhale would be beyond the ability of most OW students.

I train my divers to breathe slowly and deeply ... 3-4 seconds on the inhale, a one-second pause at the top of the cycle, and a 10-12 second exhale. That gives more than adequate time for a good O2-CO2 exchange, and keeps the divers in a comfort zone that allows them to devote their attention to all the other things they're in class to learn.

I doubt that I could succeed at a 30-second exhale ... and I'm not going to ask students to do something I can't do. And I seriously doubt there's any such requirement by PADI or any other agency out there. If there is, I'd love to see a reference to the specific part of their standards that say so ...

... Bob (Grateful Diver)

 

[Sleepdr]

That can't possibly be right ... a trained opera singer might be able to control their exhale for 30 seconds, but most normal human beings would have difficulty doing so for more than about half that, absent the expanding air on a CESA. And even then, a 30-second exhale would be beyond the ability of most OW students.

I train my divers to breathe slowly and deeply ... 3-4 seconds on the inhale, a one-second pause at the top of the cycle, and a 10-12 second exhale. That gives more than adequate time for a good O2-CO2 exchange, and keeps the divers in a comfort zone that allows them to devote their attention to all the other things they're in class to learn.

I doubt that I could succeed at a 30-second exhale ... and I'm not going to ask students to do something I can't do. And I seriously doubt there's any such requirement by PADI or any other agency out there. If there is, I'd love to see a reference to the specific part of their standards that say so ...

... Bob (Grateful Diver)

Back in my misspent youth, I played oboe in jr high band. Years later, my first career was in radio & narration, which also required good breath control. Some of my undergrad classes had segments specifically on managing breath for performance.

A moment ago, I decided to do a 30 second exhale. Based on my sample size of 1, I agree with you. Subjectively, the end was similar to how I feel at the end of 120 seconds of breath holding. I'm not trained nor practiced in apnea, so that gets unpleasant without the physics of an expanding volume of air.