cummings66
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I would say 3 reasons, the third being they're in a hurry and swim like a Sharks after them. Slow down, enjoy the sights and your SAC will drop.
Just certified for open water today! How to improve SAC rate?
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This is out of the gas management handout I give my students ... some of it may be helpful ...
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, it’s 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 … it’s what we’ve 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 … it’s 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)
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, it’s 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 … it’s what we’ve 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 … it’s 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)
... ummm... what they all said...
I've been workin' on my SAC too...
When my wife and I went down to the Keys in Mar we had a day where we made two boat dives... on the first one I had camera issues, got flustered, ran into current, ran into surge, missed the wreck, swam back, got more flustered... end of dive... SAC of .81 Second dive an hour later... solved my "cranial/rectal inversion problem"... slowed down, (same surge... same current)... and had a SAC of .61
I found that shooting video underwater was a nifty way to make my air last longer. Why? If you move too fast the resulting video will make ya' dizzy... so ya' slow down... slowing down means ya' burn less energy... which takes less air... (... and people are more inclined to watch yer' videos without reaching for a barf bag...)
Try this for a "prove it to yourself" test... arrange with your LDS to use a pool sometime... take a tank of air... go down to the bottom and spend the time practicing your bouyancy and trim. (It won't be exciting... but it can be very helpful)... don't swim around a lot... just lay there and use your lungs to stay a foot or two off the bottom... relax... enjoy the day. Then... check your SAC rate.
My wife and I did it this last weekend... I got a .36 SAC for the day... 2 hours and 4 min on 62 cu feet of air. :14:
(... and, I'd note... I'm 54 and *not* a "Mr. Universe type"... so, if I got into better shape who knows... I'd probably have to send out for lunch before the dive wuz' over...)
Then, for comparison... do another tank (probably on a different day)... and spend the time just swimming around down there... nice and easy... but keep moving...
Compare the two... I know it's intuitive... but sometimes just doing it and seeing/feeling the difference can make it real.
... and NWGratefulDiver's stuff nails down the specifics... good stuff... (I'm workin' on it Mr. Grateful!!!! I'm workin' on it!!!!!)
I've been workin' on my SAC too...
When my wife and I went down to the Keys in Mar we had a day where we made two boat dives... on the first one I had camera issues, got flustered, ran into current, ran into surge, missed the wreck, swam back, got more flustered... end of dive... SAC of .81 Second dive an hour later... solved my "cranial/rectal inversion problem"... slowed down, (same surge... same current)... and had a SAC of .61
I found that shooting video underwater was a nifty way to make my air last longer. Why? If you move too fast the resulting video will make ya' dizzy... so ya' slow down... slowing down means ya' burn less energy... which takes less air... (... and people are more inclined to watch yer' videos without reaching for a barf bag...)
Try this for a "prove it to yourself" test... arrange with your LDS to use a pool sometime... take a tank of air... go down to the bottom and spend the time practicing your bouyancy and trim. (It won't be exciting... but it can be very helpful)... don't swim around a lot... just lay there and use your lungs to stay a foot or two off the bottom... relax... enjoy the day. Then... check your SAC rate.
My wife and I did it this last weekend... I got a .36 SAC for the day... 2 hours and 4 min on 62 cu feet of air. :14:
(... and, I'd note... I'm 54 and *not* a "Mr. Universe type"... so, if I got into better shape who knows... I'd probably have to send out for lunch before the dive wuz' over...)
Then, for comparison... do another tank (probably on a different day)... and spend the time just swimming around down there... nice and easy... but keep moving...
Compare the two... I know it's intuitive... but sometimes just doing it and seeing/feeling the difference can make it real.
... and NWGratefulDiver's stuff nails down the specifics... good stuff... (I'm workin' on it Mr. Grateful!!!! I'm workin' on it!!!!!)
Zenshift
Contributor
Ditto everything thats already been said about practice and experience. Also the pacing of your breathing. I also was a horrible air suck (now a neophyte air hog) until I realized my thoughts of "MUST KEEP BREATHING" should be more of "Inhale. Nice and peaceful now ... exhale .... ahhhhhhhhh"
Good job on your cert.
:wave-smil
Good job on your cert.
:wave-smil
Spratman
Contributor
Congrats on the OW!
What everyone else said. Have someone teach you how to frog kick. It does wonders for your SAC rate, since you are not cranking as hard to move.
The other thing is practice breathing while you are at work. Slow, deep breaths in, slow exhalations. Exhale with your lips pursed, so you get resistance. It helps build your lungs up.
Also, dive, dive and dive. The more you do it, the more you want to do it!
What everyone else said. Have someone teach you how to frog kick. It does wonders for your SAC rate, since you are not cranking as hard to move.
The other thing is practice breathing while you are at work. Slow, deep breaths in, slow exhalations. Exhale with your lips pursed, so you get resistance. It helps build your lungs up.
Also, dive, dive and dive. The more you do it, the more you want to do it!
Charlie99
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Another subtle but important effect of frog kicking is that you will get neutral in the water. With a frog kick there is a significant glide portion following each kick. If you aren't neutral you will ascend or descend while gliding.Spratman:
TS&M, NWGrateful Diver, and others have covered things pretty well, so my comment is just to emphasize what I've seen to be the core issue -----
You use a lot of air if you are working too hard. If you are excited and nervous you tend to zoom around excessively. If you aren't neutral in the water, then you have to keep finning continuously to maintain depth. If you stop, you start sinking. This adds to the nervousness.
One of the hardest to learn underwater skills is learning to do NOTHING!
If you learn to maintain neutral buoyancy at all times, you can just stop whenever you feel like it, and you'll stay in the same place. Being able to do this has a very calming effect. You don't get the feeling that you need to rush around. You can slow down, look around, and take in what's going on around you.
Don't concentrate on breathing or on trying to conserve air. Just work on being able to do nothing other than just hanging there motionless enjoying the moment. At any point in the dive, you should be able to just stop all motion and ascend slowly with full lungs and descend slowly with empty lungs.
At first, it may be easiest to work on being neutral while doing your safety stop.
Charlie Allen
p.s. Proper weighting makes staying neutral easier, but even when weighted properly you wetsuit will compress at depth and you need to add air to compensate for that.
Fish_Whisperer
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Ditto on the frog kick. The gleuts, hams, and quads are the biggest muscles in the body, and therefore, require the most oxygen when they are called upon to work. Slow your kicking down, get your trim horizontal, get rid of stuff that dangles or drags, and really really relax....
A technique I've been using, is to keep my inhales long and slow, pause (without closing the epiglotis or holding my breath or skip-breathing), but pausing for a couple of beats, and then exhaling, making each exhale a little longer than the last. Pretty soon, on my better dives, my breathing is so slow, each breath so long and deep, I'm breathing no harder than if I were in a deep state of meditation, or napping on the couch.
Experience, proper weighting and trim, knowing what to expect, as well as just learning how to completely relax, are the things that will help you the most. Good luck and congratulations. Welcome to the world of scuba!
A technique I've been using, is to keep my inhales long and slow, pause (without closing the epiglotis or holding my breath or skip-breathing), but pausing for a couple of beats, and then exhaling, making each exhale a little longer than the last. Pretty soon, on my better dives, my breathing is so slow, each breath so long and deep, I'm breathing no harder than if I were in a deep state of meditation, or napping on the couch.
Experience, proper weighting and trim, knowing what to expect, as well as just learning how to completely relax, are the things that will help you the most. Good luck and congratulations. Welcome to the world of scuba!
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