Breathing
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OP
twistypencil
Contributor
Since I'm relatively noob, I do not know what RMV is or how I can follow it. Probably I would get this if I would have shelled out for the extra $300 for the AI for the perdix?
OP
twistypencil
Contributor
Thanks for that... they say 6 breaths/minute is super relaxed. Without trying hard, I do 5 breaths/minute. I guess its possible that is faster underwater
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There are many RMV calculators if it is not supported by your computer, here is one http://www.chipoladivers.com/articles/rmv-calculator/
pay attention to how people breathe when in a relaxed sleep. that is the breathing pattern to strive for. also you will notice there is usually i small pause between inhale and exhale.
the online RMV calculators are the easy way, but in case you're curious, this is how its figured out...
the online RMV calculators are the easy way, but in case you're curious, this is how its figured out...
To calculate your SAC = Surface Air Consumption, bring a slate. When you get to the bottom write your: 1) Time, 2) depth, 3) psi. Just before your ascent, while still on the bottom, check your info and write down those same data. Now you have all the info you need to calculate your SAC rate later. By the way, it's really helpful if you write blocks on your slate for the info prior to your dive. Then at the bottom you can just quickly fill in the blanks.
Back on the surface, subtract the ending pressure from what you wrote down at the start. For example, if you are diving an Aluminum 80 it would work like this. At the bottom if your psi was 2600 psi and then just before your ascent it was 800 psi, then your total consumption would be 1800 psi. An Aluminum 80 holds 77.5 cubic feet when filled to it's rated pressure of 3,000 psi. So 77.5/3000 =0.0258. That means you have 0.0258 cubic feet of gas to breath for each 1 psi.
In our example, you burned 1800 psi on this dive. So 1800 *0.0258 = 46.44 cubic feet (the amount consumed on this dive). So let's say this dive lasted 40 minutes. divide 46.44 cubic fee by 40 (min). = 1.161 cubic ft/min.
Now you know on this dive that you consumed 1.16 cubic ft/min.
Next question...how deep were you? If you averaged 60 feet (from your start vs ending depth) then calculate your consumption at depth, relative to atmospheric pressure (1 atm = 33' seawater).
60'/33' = 1.81 + 1(for surface pressure) = 2.81 atmospheres pressure.
Now divide 1.61 cf/min by 2.81 atm. =0.573 cf/min at the surface.
Once you know your SAC (this should be averaged over quite a few dives) you can estimate your consumption for any depth.
For example, lets say you really do end up with an average SAC rate of 0.573 cf/min.
If you plan a dive to 100 feet, then (100/33) + 1 = 4.03. Now multiply 4.03 by your SAC of 0.573.
4.03 x 0.573 = 2.3. So at 100' you know you'll burn 2.3 cubic feet/min.
How long would an aluminum 80 last you at that depth? 77.5/2.3 = 33.7 minutes.
Back on the surface, subtract the ending pressure from what you wrote down at the start. For example, if you are diving an Aluminum 80 it would work like this. At the bottom if your psi was 2600 psi and then just before your ascent it was 800 psi, then your total consumption would be 1800 psi. An Aluminum 80 holds 77.5 cubic feet when filled to it's rated pressure of 3,000 psi. So 77.5/3000 =0.0258. That means you have 0.0258 cubic feet of gas to breath for each 1 psi.
In our example, you burned 1800 psi on this dive. So 1800 *0.0258 = 46.44 cubic feet (the amount consumed on this dive). So let's say this dive lasted 40 minutes. divide 46.44 cubic fee by 40 (min). = 1.161 cubic ft/min.
Now you know on this dive that you consumed 1.16 cubic ft/min.
Next question...how deep were you? If you averaged 60 feet (from your start vs ending depth) then calculate your consumption at depth, relative to atmospheric pressure (1 atm = 33' seawater).
60'/33' = 1.81 + 1(for surface pressure) = 2.81 atmospheres pressure.
Now divide 1.61 cf/min by 2.81 atm. =0.573 cf/min at the surface.
Once you know your SAC (this should be averaged over quite a few dives) you can estimate your consumption for any depth.
For example, lets say you really do end up with an average SAC rate of 0.573 cf/min.
If you plan a dive to 100 feet, then (100/33) + 1 = 4.03. Now multiply 4.03 by your SAC of 0.573.
4.03 x 0.573 = 2.3. So at 100' you know you'll burn 2.3 cubic feet/min.
How long would an aluminum 80 last you at that depth? 77.5/2.3 = 33.7 minutes.
One reason a short pause helps reduce consumption is because it gives a little extra time for gas exchange at the alveolar level. More CO2 can transfer from tissues to lungs to be exhaled, and more O2 can transfer from inhaled gas into tissues with every inhaled breath. On dry land, this is inconsequential; who really cares if you get a little extra O2 with each breath, since we effectively have an infinite number of breaths we can take and will never run out of gas (at least in this century). It is very different underwater, breathing from a limited gas supply. More gas exchange with every breath means fewer breaths you have to take and also fewer breaths you feel like you need to take, since the main drives to breathe are hypercapnia and hypoxia in that order). A slower breathing pattern and a short pause may also help get you into a more relaxed state.
ScubaJCBS
Live to dive! Dive to live!
What everyone is saying is great and correct one thing I started doing was when not diving practiced breathing this way and it helped me to think about it while diving. Inhale counting 4 seconds in and 10 seconds out. Just count 1 thousand 1,2,3,4
PfcAJ
Contributor
Stop doing that.
Just breath. Do you breath some special way when you’re sitting on the couch? Nope, you breath normally.
Breath when you need to breath.
You’ll need to breath less when you’re still, neutral, relaxed, streamlined, and efficient in your movement. Any special breathing techniques are hogwash.
ScubaJCBS
Live to dive! Dive to live!
I just learned to breathe differently when wrestling, fighting and especially if your in a bad spot. Breathing techniques are proven to work everywhere but scuba, it's basically to help your mental state reduces stress and anxiety levels. But it could just be hogwash too.
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