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: "Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, chocolate in one hand, martini in the other, body thoroughly used up, worn out, and screaming, 'Oh ......... What a ride'!!!!
I'm just trying to find out what the benchmark is.
Just go do a few group dives and see when you go low on air compared to the others .
I often dive off boats that dive as two groups of 6, each with a guide. Diving with the more experienced group, it's rare that that I'm ready to go up when all of the other customers have had to surface due to low on air. Small women DMs will generally have a bit lower SAC. Many of the male DMs use more air than me. My SAC is usually around 0.4cfm on a slow dive, rising towards 0.5cfm or so when swimming around quite a bit. Based on my experience in multiple locations, those numbers are pretty much towards the bottom end of the scale.
When I buddy up with a diver that has only 10-25 dives and doesn't know what his SAC is, I plan the dive assuming it will be around 0.66 -0.75cfm (i.e. 2/3 to 3/4cfm), and that is usually in the right ballpark.
I'm trying to get a feel for what an average SAC Rate would be. I'm running around a .61 to a .68. Obviously my consumption is a little high. I'm just trying to find out what the benchmark is.
If this has been discussed before, I appologize, but I couldn't find it in my searches.
Well....this is pretty personal. There really isn't a benchmark. Everyone has to establish their own personal benchmark....
Something that might help a little is that a normal sized adult in ok physical shape will use about 12 litres (+/- .43cf) while a rest, for example sitting. The obvious conclusion is that .42 is getting towards the lower end of the scale while diving. In practice this number is pretty close to what you see. Some people can use less some of the time, getting down to about 10 litres/.35cf or so but any lower than that requires either extraordinary physical condition or cyber-superhero exaggeration.
I am roughly running .4 to .55 on an average shore dive. I have data from other dives but just haven't run the numbers. My smartCom makes it easy to calculate too.
Edit: I should add, if I get my sac rate close to .4 on occasion I get a headache during the dive from what i presume is a CO2 buildup. It doesn't feel like I am retaining too much CO2 but the headache is the feeling I get when I breathe very slloooowwwwyyyy.
Last edited by JustinW; March 1st, 2006 at 02:03 AM.
Some people can use less some of the time, getting down to about 10 litres/.35cf or so but any lower than that requires either extraordinary physical condition or cyber-superhero exaggeration.
Probably less of the former and more of the latter...
In warm water single tank dives, I tend to be around .45...Had a cavern dive in Mexico where I managed a .41. In cold water single tank dives, I tend to be around .55. Add a set of doubles and a deco bottle to that and it goes up to .65-.7 or so. Cold water deco tends to be around .55ish, sometimes more. I'm 6', 155 lbs and have very little fat or muscle...basically a twig.