Air consumption improvement

[raskous]

Wow lots of awesome tips here
Thanks so much guys for all your comments.

I'll make sure i keep all those in minds next time i dive.

I realize now what you're saying about relaxing is right, like when i went wreck diving i was using so much air because i had to focus a lot on my buoyancy so i wouldn't hit a ceiling or a beam. But then when i dived the great barrier i was just looking around at sharks and all, and i used way less air...

Thanks again guys, this is great

 

[diver 85]

You've dived with smart DM'ers in the past---"the only thing they told me was that it comes with experience:"......With experience, everything improves ie correct weight, good buoyancy, better breathing----again everything improves INCLUDING(therefore) air consumption......

 

[String]

I meant 20 bar, but 200 psi is close enough. ooops.

:inquisition:

OP I'm sure meant 20 bar too, since I'm assuming he's using ~230 bar tanks, that would mean he vents the entire tank in a few minutes...

I've seen 20 bar, just filled on the boat and off the side, 210 bar becomes 190 bar pretty easily.

p1/t1=p2/t2 .. remember to use kelvin.

Basic open water gas laws can predict exactly what it'll drop to

 

[asj]

p1/t1=p2/t2 .. remember to use kelvin.

Basic open water gas laws can predict exactly what it'll drop to

open water gas law eh?

 

[Guba]

open water gas law eh?

I'm sure Gay-Lussac would be interested in the name change of the law. Who knows? If he had been born a couple hundred years later, he might have been a scuba diver!

 

[MXGratefulDiver]

I suspect what String means is gas laws that are taught in Open Water class ... that's at least how I interpreted what he said ...

... Bob (Grateful Diver)

 

[String]

I suspect what String means is gas laws that are taught in Open Water class ... that's at least how I interpreted what he said ...

... Bob (Grateful Diver)

Exactly that - the basic gas laws are in the syllabus for all entry level open water courses and provide what you need to work out the pressure drop here.

Maybe rephrased to "the gas laws covered in the open water course"

 

[Guba]

Of course that's what was meant, gentlemen, and I think asj and I both recognized the intent. As a science teacher, though, I'm used to referring to the laws by name, and the wording just hit my funny bone. Please don't construe what I said as sarcasm or an attempt to belittle anyone. It was only meant as light (VERY light) humor. If anyone's feeling were hurt, I heartily apologize.

 

[pelagic_by_nature]

I have a couple of thoughts for this thread. In my first week of diving (I was on a week long dive trip to Roatan), I was usually the first one to hit 1000lbs. I have just recently (last Sunday) hit my 50th dive, which I was told back then, would be the point when my air consumption would drop. Well, I was listening for a switch to flip on that 50th dive, signifying better air consumption Didn't hear anything. My AC has certainly dropped, however, for all of the previously mentioned reasons - better trim, better weighting, much more comfortable in the water, but of course, it was gradual. Here's a tip I heard about 6 months ago - "you must sip the air, don't gulp the air. I notice that when I inhale, I can hear a particular pitch from my first stage (I think) that changes relative to how hard I inhale. I have come to recognize the pitch that corresponds with a slow relaxed inhale and I try to produce that particular pitch with my breathing.

 

[lmorin]

First off, as everyone has said, high gas consumption is typical for a novice diver, and it will improve as you become more comfortable with the mechanics of diving.

But what actually CHANGES as people get more experience, that explains why they use less gas? I would offer that it is two things -- they become more relaxed (and therefore breathe more effectively) and they become more efficient (so they don't work as hard).

.................

The solution is a slow, rhythmic pattern of inhalation and exhalation, with a very brief pause at the end of each swing. Some people read this as meaning you should inhale everything you possibly can, and exhale everything you possibly can, but that's not the point. If you do that, you'll have significant buoyancy changes! What you want is a slightly larger breath than what you would take sitting on your couch, more like what you would do if you were doing yoga or meditating, and a steady, slow rate of both inhalation and exhalation.
...................

Relaxation and efficiency . . . both come with time, but you can shorten the course by taking some thoughtful steps to change your gear and your procedures.

I have quoted some of TSandM's major points.

And, I would add that in my own experience, the change from being a gas hog occurred quite suddenly, within a few dives. I have been a strong athlete all my life, especially soccer, and air demand under game conditions is enormous. I was under the illusion that because I am reasonably expert and efficient with my aerobic sports breathing, the same tactics should work with diving. Wrong!

It took me about 25-30 dives to recognize the need to practice slow, not so deep, breathing. In fact, I practiced breathing as slowly (breaths per min) and as shallowly as possible, learning the limits of what worked for me--slow and steady. Along the way, I also learned that my lung capacity could be divided into conceptual thirds, full volume, middle and low volume. With practice, I learned to breathe quite slowly, as TSandM describes, inflating my lungs only to middle volume. This had an added advantage. If I needed to rise over an object while swimming, it was usually as simply as inhaling a bit more to increase volume; exhaling more would allow me to sink. My wife, who never did aerobic sports, seemed to know how to breathe correctly from the outset, but I caught up after about 30-35 dives.