Average Gas Consumption

[scubadada]

@Blackcrusader @Dan @Centrals

A SAC of 0.61 bar/min with an AL80 (11.1 L) is a very, very low RMV, 6.8 L/min or 0.24 cu ft/min

 

[scubadada]

Over 76,000 views and 16 more votes in the poll, now 894.

The median, mode, and weighted average remain 0.5-0.59 cu ft/min or 14.2-16.9 l/min.

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Enjoy your diving

 

[Blackcrusader]

0.61 bar/min on AL 80, that’s pretty impressive!

Very optimal dive conditions. Very slow current going with not against, no other divers near me as the guide and other divers on 21% so they were shallower but enjoying my bubble trails lols. I actually found some nice critters and was able to just stop and look at them for a few minutes at a time. Good visibility on some dives. This is pretty much getting into my being in my most chilled diving state.

Maldives in May I expect more of a workout

 

[Joneill]

Very optimal dive conditions. Very slow current going with not against, no other divers near me as the guide and other divers on 21% so they were shallower but enjoying my bubble trails lols. I actually found some nice critters and was able to just stop and look at them for a few minutes at a time. Good visibility on some dives. This is pretty much getting into my being in my most chilled diving state.

Maldives in May I expect more of a workout

You’re an anomaly - that is a freakishly low consumption rate. It’s also far below the normal range that anyone here should be expecting to get to!

 

[Dan]

You’re an anomaly - that is a freakishly low consumption rate. It’s also far below the normal range that anyone here should be expecting to get to!

After 20 years of scuba diving, my average air consumption is about 1 bar/min on AL80. It was 2 bars/min 20 years ago though. I managed to cut it in half after 10 years or so.

 

[rsingler]

Very optimal dive conditions. Very slow current going with not against, no other divers near me as the guide and other divers on 21% so they were shallower but enjoying my bubble trails lols.

I am in awe of that number. If I glance at my SAC on my Perdix, I can rarely see 8 psi/min on an AL80 for a tiny segment of a dive in relaxed conditions. But never a whole dive.
Speaking as a retired doc as per this post, if that was your SAC for a whole dive, and you're 70kg or more, you were right on the edge of hypercarbia, or perhaps a few mmHg CO2 into hypercarbia and were used to it.
That's been practiced for decades, but keep in mind that you may have significantly compromised your reserve if you suddenly had to exert yourself and markedly increased your CO2 production. It would be a short hop to a CO2 hit.
I'm not criticizing. You're an experienced guy. I'm more posting for those reading along. Still, cool numbers!

 

[Blackcrusader]

I am in awe of that number. If I glance at my SAC on my Perdix, I can rarely see 8 psi/min on an AL80 for a tiny segment of a dive in relaxed conditions. But never a whole dive.
Speaking as a retired doc as per this post, if that was your SAC for a whole dive, and you're 70kg or more, you were right on the edge of hypercarbia, or perhaps a few mmHg CO2 into hypercarbia and were used to it.
That's been practiced for decades, but keep in mind that you may have significantly compromised your reserve if you suddenly had to exert yourself and markedly increased your CO2 production. It would be a short hop to a CO2 hit.
I'm not criticizing. You're an experienced guy. I'm more posting for those reading along. Still, cool numbers!

Thanks for your reply. I actually weigh 125kg. I pretty much breathe the way I do on land. I do notice that when resting I exhale but then do not start to breathe in again for 5 - 10 seconds. I am not getting headaches or dizzyness or any other signs of hypercapnia that I feel. I understand that I am not medically trained and don't do a blood test after a dive either. I just have a slow breathing rate and a slow heart beat when relaxed. Was reading from page 15 - 20 again and your comments about RMV under anaesthesia.

The IDC Course director friend who is around 5ft tall and weighs very little her SAC rate is much better than mine. Also a French instuctor at the same dive center is slightly better than I am although he is around 175cm tall and weighs around 70kg. However none of the Philippino guides

On this trip I was put in groups with several instructor cert divers. One of the German CMAS instructors noticed with the dive briefing with the guide I would dive with the group to whatever max depth they would set which was always max 30m then just stay deeper than 20m after they ascended. This would normally mean I would get to around 50 plus minutes before I would ascend to around 10m then later on ascend to do the safety stop. He complemented me on my diving and gas consumption. He did say I was unusually good on air and he could not match that.

So on dives where I had my camera rig and was doing more activity to get shots my rate was around .7 bar/min. But when I had no camera rig I dropped that to .60 - .63 on this trip But the main thing was that the guides knew I would just hang around the 20m depth for as long as my NDL allowed.

Also at times groups were close together after 50 - 55 minutes and fun divers would see me signal to the guides the half tank sign and look a bit shocked. Other divers would ask me what my secret was. I just replied being still not chasing turtles and other critters when you saw them and being totally relaxed. Also I was the laziest diver in that I did not move around a lot.

 

[Blackcrusader]

You’re an anomaly - that is a freakishly low consumption rate. It’s also far below the normal range that anyone here should be expecting to get to!

Yeah I do not know that other people cannot get to it. I know some who do. A few guides and a couple of instructors. A good dive buddy instructor from the UK has improved his gas consumption diving with me and we are off to Maldives in May. I am going to log every dives pressure start end and see if our average depth is similar. Will be just on 21% but will be good as we should do around 50 dives together.