SAC Rates

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

AevnsGrandpa

Contributor
Messages
484
Reaction score
10
Location
Bloomnigton, Illinois
# of dives
50 - 99
Hi all,

I know this has been discussed and when I searched on SAC it found nothing so I start a new thread...

What is considered a good average SAC rate? I know that is a real ball park question but I have been diving for only 3 years and have 40 dives in and have been keeping track of this in a spreadsheet for each dive and didn't really know what is good and what is bad. My average is .6175.

Thanks and if there are any threads I didn't find or links with info about this I would appriciate them too!

Jeff
 
well, it does depend from diver to diver (gender, age, fitness), etc...

but generally speaking, i'd be ecstatic for anything under .4 cfm, happy
for anything under .6 cfm, and resigned to my fate for anything under .8 cfm.
i'd be unhappy with anything over .8 cfm

as an ex-smoker, i have a horrible .72 cfm average
 
I typed surface air consumption into the search feature and came up with far to many threads to cut and paste. Plenty of reading:D

IMO with more frequent diving and experience you could expect your .6 to drop closer to .5.

PS--More important than what your actual SAC rate is--do you know how to use that number for dive planning?
 
I am new to diving (a whole 8 dives since certification and buying my dive comp) for my 8 dives I have done so far my SAC is around .46 cfm. I am a smoker but am very comfortable in the water and not very large ( male, 5'6" 140lbs.) so I guess that helps some.

Now if I would just stop smoking and start diving more Id be doing pretty good.
 
dhampton82:
Now if I would just stop smoking and start diving more Id be doing pretty good.


you should quit smoking (it's terrible for you) ... but prepare to have your SAC
go up, not down ...

i went from a SAC in the .40's to a sac in the .80's after i quit smoking. it's
back down to the low .70's now ... but it still sucks compared to before.
many, many ex-smokers have experienced this.

but this is no reason not to quit smoking, though. please do. i feel ten zillion
times better, and i enjoy my dives all the more
 
maybe i should smoke a cuban after each dive to improve my SAC. :)
 
H2Andy:
you should quit smoking (it's terrible for you) ... but prepare to have your SAC
go up, not down ...

i went from a SAC in the .40's to a sac in the .80's after i quit smoking. it's
back down to the low .70's now ... but it still sucks compared to before.
many, many ex-smokers have experienced this.

but this is no reason not to quit smoking, though. please do. i feel ten zillion
times better, and i enjoy my dives all the more

This has to do with the fact that smokers become CO2 tolerant to the degree that they are effectively skip breathing at depth. The low SAC of a smoker is thus a very bad thing.

Cameron
 
I had'nt really thought about SAC untill I read a similar thread the other day. I went back to my dive log and figured my SAC's to see how mine was.

Boy was that insightfull. My first few dives were around 1.2-1.5 now I am down to .4 - .5 I'm really surprised to see that much of a difference when I haven't really been working on it, just diving as much as I can.
 
So, a question from a noob, hopefully for the benefit of other noobs.

How do you improve your SAC? I seem to be always on the high end of the groups I have dove with (which means that I am usually the one causing the dive to end, based on air, rather than No-Deco time) and would like to improve - I average somewhere between 0.65 and 0.9 depending on what I am doing and I definitely see a pattern - the easier dives where I was less taxed I use less (logical).

my goal it to try to get myself to the point where the air isn't the obstacle - what stops my dives are the No-Deco times. I use at 80Al tank to-date and I know I could go to a 100, but would rather just get better at diving than carry a bigger tank (I know I have this in my "back-pouch" in case i can't actually improve....)

But in general - what are the things to do?

The obvious ones to me seem to be to get in better cardiovascular shape, and to learn to relax more underwater (my instructor taught me this slow breath technique - long inhale, then break your exhale into three sections, holding very briefly between (about the time between inhaling and exhaling).

Another thing could be to manually inflate your BC underwater, rather than just using tank air, but I wonder if that would really make that much of a difference, and then you are faffing about with your regulator and BC inflator...

So do the more experienced divers have any tips they could impart to the rest of us? What worked for you?
 
Your ideas are right,

The only thing I can say is that SAC will improve over time, when you feel comfortable under water. I know many people say 'I feel comfortable already'. I dont know how to describe it, things just come naturally after a while, then SAC starts going down on its own.
 

Back
Top Bottom