JMcD:
I'll be a better buddy when I get in shape and stop cutting my buddies dive short by sucking a tank of air so fast.
Getting in shape can help ... but I know some very out-of-shape divers who are very good with air consumption.
Here are some tips from a paper I just e-mailed to another ScubaBoarder that will help you improve your air consumption considerably ...
Breathing
Scuba diving presents most of us with the first time in our lives that we have ever actually had to think about breathing. For the most part, its something we just do and never give a whole lot of thought to. But underwater it affects us dramatically. And there is a technique to proper breathing on scuba gear. In general, you want to take long, slow, deep breaths. A complete inhale and exhale should take anywhere from 5 to 8 seconds
sometimes longer for more practiced divers. Rapid breathing affects our buoyancy
shallow breathing tends to build up carbon-dioxide in our body, which causes us to feel oxygen starved and breathe harder and faster. Practice long, slow, deep breathing on land
and then try it in the water. You will often notice an immediate improvement in your buoyancy control, and over time will notice that as your buoyancy control improves, so does your gas consumption.
Weighting
Improper weighting will affect your gas consumption considerably. Divers who are overweighted will go through their gas faster because they have to carry excessive gas in their BCD or wing to maintain neutral buoyancy, and even small changes in depth will cause excessive changes in their buoyancy because of the expansion or compression of that extra gas. You should perform weight checks any time you get a new piece of gear, and occasionally as your diving skills improve, because simply learning how to relax more underwater will often allow you to lose weights you thought you needed. Conversely, underweighted divers will struggle to stay down
working harder than they need to, which will also cause you to breathe harder than you should and consume your gas supply at a faster than needed rate.
Trim
Humans are psychologically oriented in a vertical position
its what weve done since we learned how to walk, and when learning scuba we must teach ourselves to move about in a horizontal position. Proper trim is very important to good gas consumption. Water is 800 times heavier than air, and we cannot efficiently move through water in the same way we move through air. Maintaining a horizontal position means that as we move through the water, we have to move less water out of our way than we would in a vertical position. It also radically increases the efficiency of our fins to move us in the direction we want to go. Both of those are huge factors in terms of our air consumption, because it reduces the amount of work we need to do to move about.
Swimming speed
Many divers, new divers in particular, tend to swim rather quickly. While that will get you from point to point faster, it will also increase your air consumption dramatically. In fact, the faster you go the more air you will consume getting from one place to another. Slow down
its not a race! There are lots of tiny creatures (and even some large ones that are good at camouflage) that you will miss if you speed by. Going slow, and keeping your fin kicks relatively small, will improve your air consumption dramatically.
... Bob (Grateful Diver)
