SAC Rate Poll What is normal? MALES ONLY

[MXGratefulDiver]

What I want to know is, if there are so many air sippers out there, how come I never see you on any of you on the boats I'm diving?

Mebbe you're diving on the wrong boat ...

Seriously, since this poll started I've been tracking my own SAC on every dive ... and it spans about four categories, depending on depth and conditions.

... Bob (Grateful Diver)

 

[RIDIVER501]

I tested the spread sheet by inputting the following
3000-2500
2500-2000
2000-1500
1500-1000
1200-700
All have delta P's of 500psi, so the SAC rate should have been the same becuase all other factors were in the spread sheet were unchanged.
but they weren't so I tweaked the formula based on Simbrooks calc post

A lot of people dont calc out exact numbers for Vf on every dive (or at least record them), so to find Vf = P1/Px*Vx
Where:
Px = rated tank pressure (likely 2400, 2640, 3000, 3442 or 3500) in psi
Vx = rated tank pressure at Px and of course SRT (standard room temp)

or you can rewrite that whole thing as:
(P1-P2)/Px*Vx/Aa/Tm

Aa of course is the average atmospheric pressure throughout the dive, not the deepest point.

Mine seems to be around 0.42 +/-, but that is in warm water Under stress, in caves or cold water it climbs to around 0.55-0.6 depending on flow.

Now the spread sheet is working fine.

Thanks Charlie 99

 

[Daryl Morse]

I know the poll is closed, but I figured I'd throw my numbers into the lot since I used my Apeks computer for the first time yesterday and downloaded the data into the dive log software. (Aren't gadgets fun?)

For dive 28, the max depth was 88, average depth was 55, dive time was 36 minutes and SAC was 0.6 cfm.

For dive 29, the max depth was 94 (brief bounce), average depth was 61, dive time was 33 minutes and SAC was 0.62 cfm.

Yah, I know we should have stayed shallower for the second dive, but we had almost 3 hours of SI.

FYI, the water temperature was 46F/8C and the air temperature was 50F/10C (I'm still cold). I was diving dry.

 

[Daryl Morse]

I have no idea why my calculated SAC would be higher on dives that are deeper... but that seems to be the case. Not by much... but it is something that I have noticed. Perhaps it has to do with a subtle increase in work load... perhaps the darkness... perhaps... I dunno.

Wouldn't this be due to the increased use of air for buoyancy compensation (BC/DS) as you go deeper? It's got nothing to do with workload or conditions. It's a parasitic load that increases linearly with depth.

 

[pasley]

Wouldn't this be due to the increased use of air for buoyancy compensation (BC/DS) as you go deeper? It's got nothing to do with workload or conditions. It's a parasitic load that increases linearly with depth.

Hmmm, I had not considered that. You just might be on to somthing there.