1 tank over within 36 minutes

[o2dependant]

I bet your itching to put all this new info to the test!!

36 mins aint that bad - 40 will be almost a 10% improvement

So don't expect to get a huge improvement in a couple of dives. If you can get a few weekends in back to back I think that will benefit you. I had a DM that joked about my air use at first and it was not that bad IMO. I remember feeling a bit embarrassed about it. But after a succession of dive ( on holidays) and a few weeks break something just clicked.

My air use has become a bit of an obsession of mine or at least something I use to gauge how my dive went. I plan now on getting an air integrated Dive computer that I will be able to chart my use and see how I can improve it by fine tuning each variable that contributes to it. At the same time work on my fitness and general health. I've never been able to keep up any sort of fitness regime so hoping that this will be my drive to get down the gym or out running.

 

[meagicano]

that would be a norm for some one starting out.

ps: if you are a guy, never ever ever compare your breathing to a women - they just don't breathe under water

That's true! I dive with a few girls and we always beat the men even with 120s vs their 130s.
We have some people that dive regularly with us on our Wednesday might club dives that just Hoover through air. One guy has been diving for years and we've tried to work with him but on 120s (most of us dive steel tanks, 120 is the most popular but some have 130 or 150s) he still goes through air like crazy.

Buoyancy control, relaxed frame of mind (my first few dives after a medical issue led to using much more gas because of stress and worry) and even being zen underwater will help you. Diving shouldn't require a ton of exertion.

 

[Zen Diving Inc.]

Breathing anything close to that underwater would leave me with a CO2 headache pretty quick, and I am sure on land too. A relaxed breathing pattern for me is more like 3/4. My experience with trying to control breathing and slow down breathes usually winds up with skip breathing, and headaches. I have found it much better to relax, let my body use what gas it needs, and it all falls into place.

The normal respiratory rate is 12BPM at rest (not sleeping) which works out to breathing in and out over a 5 second period. The average lung capacity is 6 liters however only a fraction of this is normally used in regular breathing about .5 liters, this is called tidal volume (what goes in and out). Lets quickly do the math here:

.5 liters (TV) x 12BPM = 6 liters per min or .212 cu ft. So on the surface an 80 cu ft tank filled properly would give us 2265.35 liters. Divide that by 6 and we should be able to breathe off this tank for roughly 377 min.

Depth consumption rate = surface consumption rate x atmospheres absolute

I'll go with 55 ft since thats the average depth around Palm Beach.

6 liters X 2.66.. = 16

DCR is 16 liters per min... Which works out to 141 mins? Wow... If I could only achieve such greatness...

All of this math is based off using 100% of the air in the tank which we know doesn't work... Considering minimum operating pressure for regs to work and what ever we choose to surface with it...

The other version:

We will still use 12BPM as that is what i've been counting while just sitting here... I believe the average tidal volume is closer to 1-1.8 liters while diving and the results of that work out to be 40 -70 mins of bottom time. Which seems to be the normal range for divers at that depth around here. I know I said breathe in and out for x amount of seconds... What I meant to say was count to eight and count to sixteen. The purpose is not to slow your breathing beyond normal resting breath's, its to control how you breathe and in essence keep your mind focused on building a habit of normal breathing underwater instead of the excited can't believe i'm doing this wait was that a turtle wheres my camera erratic breathing behavior...

 

[Peter_C]

Well there is a big contradiction in your own advice.

1) Breath control: Breathe in for 8 seconds (sip the air) breath out (slowly) for 16 seconds. Practice at home, if you experience difficulty reduce rate to 6/12 then move up when ready.

The normal respiratory rate is 12BPM at rest (not sleeping) which works out to breathing in and out over a 5 second period.

So you went from a 24 second breath down to 5 seconds

I don't care what resting rates are and the math doesn't interest me either. Not having a CO2 headache does, which to me means breathing what my body tells me too.

Sac rate should be of interest overall though, as it that helps determine approximate bottom time before hitting min gas.

 

[Doc Harry]

if you are a guy, never ever ever compare your breathing to a women - they just don't breathe under water

When I hit 700 p.s.i. my GF always has about 1,800 p.s.i. remaining.

I think I saw her sprout gills the other day.

 

[Zen Diving Inc.]

Well there is a big contradiction in your own advice.




So you went from a 24 second breath down to 5 seconds

I don't care what resting rates are and the math doesn't interest me either. Not having a CO2 headache does, which to me means breathing what my body tells me too.

Sac rate should be of interest overall though, as it that helps determine approximate bottom time before hitting min gas.

Well if you read my last reply that you quoted (all of it) then you would have read my correction to the original statement. My correction says count to 8 not 8 seconds. That time of course would vary depending on how fast you count, now wouldn't it? The point being not to slow your breath below a normal resting rate - but to achieve that by focusing on something (counting) to allow your body to do this underwater. For someone who has experience as a diver this may not be useful as you have obviously found away that works for you. However when someone is asking for help this method works and has worked with my students very well, none of which have complained about CO2 headaches. Im only responding to your original comment against it, not trying to get you to do it.

By the way 12BPM @ 5 seconds per tidal exchange is done with no additional effort. Talk to someone who does Yoga, TAI CHI or any form of meditation and you will find those numbers to be completely different. Some numbers may be as low as 3BPM with a much higher volume exchange like 3-4liters...

 

[Neverland]

I bet your itching to put all this new info to the test!!

36 mins aint that bad - 40 will be almost a 10% improvement

So don't expect to get a huge improvement in a couple of dives. If you can get a few weekends in back to back I think that will benefit you. I had a DM that joked about my air use at first and it was not that bad IMO. I remember feeling a bit embarrassed about it. But after a succession of dive ( on holidays) and a few weeks break something just clicked.

My air use has become a bit of an obsession of mine or at least something I use to gauge how my dive went. I plan now on getting an air integrated Dive computer that I will be able to chart my use and see how I can improve it by fine tuning each variable that contributes to it. At the same time work on my fitness and general health. I've never been able to keep up any sort of fitness regime so hoping that this will be my drive to get down the gym or out running.

Thank you, yes I think you are right I will need more time of course..

---------- Post added December 19th, 2012 at 03:00 PM ----------

I learned to dive in a dry suit. It does make life a bit more complicated, but it can certainly be done. We have trained quite a few students in dry suits.

The divemaster is not responsible for your weighting -- you need to do a weight check yourself to know for sure you are carrying the right amount. As a general rule of thumb, if you sink like a stone once you let the air out of your BC, you are probably overweighted. You should start the dive no more negative than the air in your tank, and five pounds negative will give you a nice, gentle drift downwards.

Tks I will try learning dry suit. It can't be that hard. I'm sure I will be able to check if sink like a stone or not without air in BC, tks for the tip

---------- Post added December 19th, 2012 at 03:02 PM ----------

I've been diving a little over two years and had the sameproblem; I would always run out of air before my dive buddy as he's a much moreexperienced diver. He dives with a Al 80 so I bought a 119cuft steel tank, andnow we usually run out of air at the same time. It's a little heavier but I'mwilling pay that price to stay longer.

In case you can dive a lot it sounds like a good investment and a good opportunity.

 

[Love4Diving]

Don't worry, it will get better over time. For now you can start with learning to relax and breathe slower and deeper. You may think breathing more deep will make you use air faster but it doesn't.

Also carry as little weight as you need to easily sink. Don't use your arms to swim, and relax.

 

[Neverland]

Thank you lovediving