Once a gas hog...

[SparticleBrane]

When you exhale, you don't create a vacuum. The air that occupies your mouth, throat, and lungs after you exhale is CO2 rich air. The first bit of air that you inhale, is that same air that was leftover from when you exhaled. That's called dead air space. Now when you're under water, you also have the air that's in you regulator 2nd stage. Unless you purge your regulator after each time you exhale, then that air, that did not get out of your regulator 2nd stage, is CO2 rich air. That's more dead air space. This is why divers are recommended to breathe deeper and exhale more fully underwater. If you breather shallow, then you end up with a larger concentration of CO2 in your lungs, which makes you tired and gives you headaches.

Ever taken a reg apart? The "dead air space" inside your reg is ridiculously small, and doesn't really matter in the long run.

 

[bubba105]

All good stuff. Buoyancy/trim and dive, dive, dive.

I was taught and dive with people who have literally thousands of dives. One guy, an old friend, over 10,000. It's amazing how little air you really need. They tell me "sip your air". Another thing they stress is the cleansing breath. CO2 in your lungs is what triggers you to take another breath. If you are breathing quickly, either from stress or working, you are not getting all the CO2 out of the bottom of your lungs. That gasping or sucking breath is my alarm. So what you do is get all the air out of your lungs, push it out, then take a long, slow breath, imagine breathing through a straw. It actually feels cool and definitely has a calming effect. You'll be surprised how quickly your breathing will come back to normal doing this. If you think about it, when you finish running , you breathe in, slowly and deeply, through your nose (not possible while diving) and out through your mouth, the larger, more direct opening, to bring your breathing back to normal.

Never seen a trim weight, but, I fish, so I bring two 8oz. fishing sinkers with me on dive trips. I use 7 lbs with a 3mm full suit and since 2 and 3 lb weights is all they seem to have, I get two 3's and add my own 1/2 lb, on each side, so I'm even. I can feel the extra lb make me list to one side if I go with 4 and 3 lbs. The gurus mock me but I can use my breath to control buoyancy at 50 feet, with no air in my bc. I went from HOG, sucking a tank inside out, to bringing back half a tank. It's all due to their tutelage but I'd never tell them. I do, however, buy more than my share of after dive beers.

 

[ippy01]

I lost 30 lbs. in the previous year and absolutely saw a positive impact on my air consumption.

 

[lamont]

Wait! _You_ want to solve a skill issue with equipment???

:mooner:

the nice thing about this problem is that once you stop stressing out over your SAC rate and just work on buoyancy and trim and hovering you'll find that your SAC rate has magically gotten much better...