Calculating air consumption SAC / SCR / RMV

[roakey]

Folks may want to refer to three good existing threads on SAC:

http://www.scubaboard.com/t6810/s.html
http://www.scubaboard.com/t4339/s.html
http://www.scubaboard.com/t7661/s.html

Roak

 

[BigDiver]

Thanks for those links. They have a ton of good information. I guess I wasn't typing in the right words for my search.

I suppose I will just dive, dive and dive some more to get my SAC down.

Thanks again

PS.. those are some amazing rates or air comsumption

 

[Aquamore]

mine averages out to be around 6.75 litres per minute in warm conditions.

As for Ice diving - it goes up to 12.5 litres per minute
(even in a good dry-suit!)

Aquamore
May your bubbles go up and your air consumption come down!

 

[sumguy]

Thanks for the info, Walter. I'll have to try it on my next dive; if I can convince my buddy to just hang out for ten minutes, that is. Maybe while doing a safety stop...

 

[ScubyDoo]

Originally posted by Uncle Pug

ScubyDoo...
Give an example of how you use your SAC...
Or did you already?

UP,

Example:
I plan to use it this weekend when planning my AOW deep dive for getting a ballpark figure on how long my air supply should last.

Is that the type of example you were looking for?

 

[Uncle Pug]

Originally posted by ScubyDoo
Is that the type of example you were looking for?

Yes... and I also wanted to take a quick, friendly slap at you for using SAC the wrong way... The lowest SAC on the block isn't the goal.... much better you should have a handle on what your *real world* consistent SAC is. Since you are diving with a buddy the highest SAC is going to run the dive anyway, right?

Now to be more specific.... just how do you plan to use your SAC in figuring your gas management for the AOW... go ahead and give us a scenario.

 

[Spectre]

Originally posted by Uncle Pug
The lowest SAC on the block isn't the goal.... much better you should have a handle on what your *real world* consistent SAC is

One thing a friend of mine pointed out. Your SAC on a nice relaxed dive isn't going to help you much. Some in planning, but not really. The more relaxed you get, the better your SAC is going to get, and the more dangerous that knowledge can be. Try rapping yourself up in some monofilament and then calculate your SAC... That's the one your going to want to use... plan your dives with the SAC that you would have if you were paniced!

 

[ScubyDoo]

Originally posted by Uncle Pug

Yes... and I also wanted to take a quick, friendly slap at you for using SAC the wrong way... The lowest SAC on the block isn't the goal.... much better you should have a handle on what your *real world* consistent SAC is. Since you are diving with a buddy the highest SAC is going to run the dive anyway, right?

Now to be more specific.... just how do you plan to use your SAC in figuring your gas management for the AOW... go ahead and give us a scenario.

I never said a low SAC was my goal.....did I? NO!! I simply stated what my range was, and followed up with what my lowest was. Excuse me for answering the question that was asked.

Now to answer your question. I was going to use my avg. SAC rate to get a BALLPARK figure (as I stated previously) as to how long my gas MAY last at depth. But now that I have been *****slapped by the mighty Jacque Cousteau....err...I mean Uncle Pug, I guess I'll just can that idea and rely solely on monitoring my computer (which I obviously would have done anyway).

By the way, I failed to see the "friendliness" in your slap. Sarcastic would be a better description!

 

[Uncle Pug]

Originally posted by ScubyDoo
I guess I'll just can that idea and rely solely on monitoring my computer (which I obviously would have done anyway).

ScubyDoo, it was friendly... sorry.

Anyway... don't can the idea... go ahead and use your SAC to figure gas for your AOW dive.

Here is a scenario for anyone viewing the thread to jump on:

Let's say you are doing a dive to 100 fsw for 10 minutes and then 70 fsw for another 15 minutes finishing by putzing around at 30 fsw until your time or gas hits the bricks. With moderate exertion in cold water how long do you have at 30fsw and what are your steps in finding out the answer. You choose the tank.

 

[Uncle Pug]

I posted this little exercise on actually using SAC for something almost a month ago and the thread suddenly died!

Finally outta the blue...
(well actually outta the PM department)
Comes an attempted solution...

So there is actually a learner amongst us...

And there really is a use for SAC after all.