Hit a brick wall with air consumption

[Joeyk]

Hi all,

My air consumption rate is around 20L per minute in warm water (pretty bad )

Ive worked on my buoyancy alot over the past year and keep pretty decent trim in the water, I frog kick to conserve energy (kick, glide, kick), I feel pretty relaxed and do slow, deep breathing. I dont really see huge areas where I could improve to decrease it more. Am I destined to just always have a high SAC?

I was thinking of using a 15L tank more regularly. The only problem I see with that is that having all that air might become a bit of a crutch, and maybe Ill start developing bad habits with it.

Anyone else had this problem? Thanks

 

[Tortuga68]

Sometimes the more you think about it the worse it gets. Just go diving and enjoy it

 

[Bedros A]

20L/min for on a 12 Liter tank is approximately 120 mins (If my math is correct).

Thats not bad, at least not as bad as you make it out to be ... I dont know how experienced you are, but I agree with Tortuga..just dive and eventually you'll see your SAC getting better

 

[DevonDiver]

As Tortuga68 said, don't over-think it. I found that my biggest reductions in air consumption came when I stopped worrying about my air consumption. I put that down to reducing the anxiety associated with worrying that my air consumption was going to limit my buddies dives etc etc.

Keep working on the buoyancy, weighting, trim and propulsion - you can never get 'too good' at that. And try and cast aside any preoccupation and anxiety about your air consumption... it'll work itself out.

Just go and enjoy more stress-free, leisurely dives.

 

[knotical]

What triggers breathing? CO2
How do we get rid of CO2? Exhale

You might want to try focusing on more complete exhalations.

 

[DivemasterDennis]

Air consumption is as individualized as finger prints. Some factors are not changeable- like lung size, metablic rate, and the like. The other posters are right, you will use less air the more experience you have, because you will bne more comfortable and less excitable in the water. You can also work on the variables you can control:
1. maintain neutral buoyancy- you noted this- it's #1
2. move less- move slowly, enjoy the sights
3. check your weighting- don't overweight or underweight
4. check you equipment- sometimes there is air loss through "bleeding" connections on anything connected to your air source, including your bc ansd regulator. Consider a different style of regulator.
5. be aware of your depth- if you are consuming faster than the group you are with, stay a few meters above them- it will make a difference
6. relax relax relax

Good luck! Happy diving!

DivemasterDennis

 

[Rhone Man]

Plan B: hit the gym. You'd be amazed how your air consumption goes down when you get into better physical condition.

One of my regular dive buddies and I have pretty close SACs. Last year he was training for the Commonwealth games and has gas consumption dwindled dramatically.

 

[Tortuga68]

20L/min for on a 12 Liter tank is approximately 120 mins (If my math is correct)

It is if you're on the surface

But you're correct that 20L/min is not bad for SAC

 

[LIdiveGirl]

Honestly, it might sound weird but I have improved my students air consumption greatly after having them try one easy thing, pick a favorite tune and hum it while your diving, by extending you exhalations, your air consumption will improve. Its also soothing and you can change your tune to your dive : )

 

[Kevrumbo]

Go on a tropical drift dive with the current, relax and enjoy the scenery flowing by:

My SAC/RMV in tropical warm waters is typically 30% better than it is in temperate cold SoCal homewaters. However, after a week drift diving in Palau 30deg C water temp, I've lowered that to around 50% of my nominal cold water SAC (from 22 litres/min to 11 litres/min).

This is how I used this value with a 11 litres/bar tank (i.e. an AL80) in Palau:
11 litres/min divided-by- 11 litres/bar equals 1 bar/min pressure SAC rate.

All my dives are averaging 20 meters depth going with the drift current; 20 meters is 3 ATA (divide 20 by 10 and add 1 gives a depth in atmospheres absolute of 3 ATA).

Therefore 1bar/min multiplied by 3 ATA equals a depth consumption rate of 3 bar/min at 20 meters. Checking my bottom timer every 10 minutes, I expect to consume 30 bar (3 bar/min multiplied by 10min equals 30 bar), and accordingly my SPG should read 30 bar less in that 10 minute time frame.

So by 30 minutes elapsed dive time at 20 meters, I expect to be down 90 bar or at half tank (AL80 full tank is 200 bar). At 40 minutes elapsed time, I'm ascending off the wall into the shallow coral plateau around 9 meters (down 120 bar from 200 bar total, or 80 bar remaining in tank). And finally at the 45 to 50 minute mark, I'm at 6m and my 3-5min safety stop with 60 to 70 bar left. I surface and I know even before looking at my SPG that I have around 50 bar remaining in my tank.