Sac

[dreamin']

OK. I have my first dive computer, a Suunto Vyper. I went diving with it for the first time. I loved it. I printed out the profiles and staring me in the face were two concepts I would like to see a more detailed discussion on: surface air consumption and SCFM. What do they signify? How can I use them to improve my air mangement. I understand the lower the SCFM number is the better but what is a reasonable goal? For what it's worth the scfm on the first dive was .79and the second was .77. After bouyancy control air management is next hurdle. Thanks in advance for the responses!

 

[diverbrian]

I will assume now that you are watching it, your air consumption will decrease. I run somewhere under a .4 in warm water and .6-.7 typically in a drysuit. The .7 is with my doubles and .5-.6 is with singles. In class, where all I do is hover and watch students for the instructor (ocassionally following one up to the surface if they have a problem), I run a lower air consumption than when I swim out and explore.

If you are a larger person, you will go through more air than if you are smaller. If you are an athlete, you will run a far lower air consumption than if you are typically a couch potato. If you are comfortable, you will breathe more evenly than if you are stressed.

Nobody here (in my opinion), can tell you how low your air consumption should be. There are just too many variables. But congratulations for taking a look at it and paying attention to it. It can't help but improve your diving.

 

[navy85]

... http://www.scubaboard.com/showthread.php?s=&threadid=28013&highlight=SAC which does go into a bit of detail on SAC. Also, here's a website link that has a more technical discussion of SAC - Surface Air Consumption Rate