What is average surface air consumption?

[H2Andy]

I figured mine out today. It usually averages between .30 and .35.

:blahblah:

 

[waterbearer]

:blahblah:

Oh...now I am gonna post it! :lol:

 

[TheRedHead]

I took those averages on deeper dives though. You guys probably don't want to know what the average was calculated on shallower ones.

:huh: It's SURFACE air consumption. Shouldn't matter how deep you are. Working harder would increase it. Colder water tends to increase it. More drag as in wearing doubles would increase it.

 

[waterbearer]

On shallower dives...typically you are not working as hard and your heart rate is likely to be lower as well...so it would affect the conversion to surface air consumption.

Or maybe I'm just an idiot.

 

[Storm]

Boy as a rookies these numbers hurt.

Male
42
200 lbs
5 '9
Averaged it ouy over my first 11 dives....
.76

All cold water dives in wetsuit with current
Guess I've got a ways to go.

 

[TSandM]

I wouldn't even be brave enough to try to calculate the SAC on my first dozen dives, even if I had the data! There's a very definite learning curve in terms of relaxation and efficiency underwater, and it's real steep at the beginning.

 

[ShakaZulu]

I'm just wondering how my air consumption compares to others. I have no idea if it's good, bad, or average. I don't seem to run out sooner than anyone else, but I kinda think I might be a bit of a hoover for my size. If you're willing to share your info, here's mine. I'm including lots of stats because I know theoretically it matters if you are a big guy comparing to a small woman. Although my dive instructor is a really big guy, and I am a smallish woman, and I know he breathes better than me.

Female
44
5' 1"
115lbs
drysuit
usual scr as calculated by my vytech is .46 -.48

Thanks! If you have any tips on how to conserve safely, please do!

That is pretty good.........don't worry about it.

 

[Cave Diver]

:huh: It's SURFACE air consumption. Shouldn't matter how deep you are. Working harder would increase it. Colder water tends to increase it. More drag as in wearing doubles would increase it.

I think the point she was making is that shallower dives tend to be more relaxed, less stressful, less work, therefore lower SAC rates.

 

[TheRedHead]

I think the point she was making is that shallower dives tend to be more relaxed, less stressful, less work, therefore lower SAC rates.

I've had stressful shallow dives in muck and relaxed dives drifting at 120 feet in Cozumel. But I understand the point as it relates to stress.

 

[Charlie99]

My SAC was 0.75cfm in the first dives. About 0.6cfm around dive #75. 0.5cfm after dive #130, gradually going down to a very repeatable 0.4 to 0.43cfm around dive #200.

Right now, my SAC is about 0.35cfm in a no motion drift, about 0.5cfm at a transit speed of 1kt (100'/minute), and 0.6 or 0.7cfm while swimming hard.

------------------

These numbers, as are most so far posted, are lower than what you see on a typical resort boat. Rarely do I end a group boat dive with less than 1000psi.

A diver with a 1.0cfm SAC will stand out as an airhog.
At 0.75cfm, you may or may not be the first one up out of a group of 6.
At 0.6cfm you are at the average or better than a typical diver in a resort place like Cozumel, Maui, or the Florida Keys.

SAC is best treated as a number that you use for planning, and a number that gives you some feedback on how efficiently you are swimming.


(This question is pretty common. The above replies are just cut and paste from http://www.scubaboard.com/showpost.php?p=887981&postcount=10 and http://www.scubaboard.com/showpost.php?p=1140040&postcount=14 )