Some reflections on SAC rates

[Rhone Man]

I recently conducted a slightly informal experiment on my personal SAC rates recently.

Two weekends ago I was in Cayman, and I did a total of eight guided dives over two days. Very relaxed slow pace, led by a DM. According to my computer my SAC rate varied between 0.37 and 0.39 cu ft per min.

Last weekend I was back in BVI - same me, same water temperature, same gear. I did three dives, but all three dives were solo dives, in much lower visibility waters, hunting lobster. Two dives had moderate current but the last dive had no current at all. For each dive my SAC rate was 0.62 cu ft.

Probably no surprises there (except for the fact that no current on my final dive in the second set didn't reduce the SAC), but interesting when you strip out a lot of the variables to see such a direct correlation in change of SAC rate attributable to a single factor.

 

[Bob DBF]

I also have found that "doing nothing" can reduce my SAC rate, although not as much as yours. I would like to get back into warm water and good viz to see what effect it would have. Last time I was in the Caribbean, I was on tables and wasen't keeping a log.



Bob
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I may be old, but I’m not dead yet.

 

[Hawkwood]

Cool. It certainly is more relaxing just to follow along. I have always "felt" that was the case when doing navigation versus just following. Really big difference when leading "students" versus leading "divers".

Bill

 

[rhwestfall]

Throwing in a camera, and I have gone from 0.6 to 1.0..... (deep/cold water diving)

 

[zider]

Cool. It certainly is more relaxing just to follow along. I have always "felt" that was the case when doing navigation versus just following. Really big difference when leading "students" versus leading "divers".

Bill

I haved noted the exact same thing. Following a buddy in the quarry I use up to 0.2cf/min less at times over when I am leading.

 

[fire_diver]

It all boils down to the stress level of the dive. This is the reason we always give the same advice to new divers asking about SAC. Just keep diving.

Familiarity = relaxation

 

[Rhone Man]

It all boils down to the stress level of the dive. This is the reason we always give the same advice to new divers asking about SAC. Just keep diving.

Familiarity = relaxation

I prefer the word "adrenaline" (not sure bug hunting in low viz is "stressful" exactly, but it certainly has your blood pumping faster), but yeah.

 

[fire_diver]

I prefer the word "adrenaline" (not sure bug hunting in low viz is "stressful" exactly, but it certainly has your blood pumping faster), but yeah.

Adrenaline is one of the body's responses to stress.

Not all stress is bad stress. Laughing is stress. Having your heart race because of a pretty girl is stress.

 

[Aqua-Andy]

Having your heart race because of a pretty girl is stress.

No, that is not stress. Real stress happens when your wife catches you looking at the pretty girl:depressed:.

 

[spectrum]

I recently conducted a slightly informal experiment on my personal SAC rates recently.

Two weekends ago I was in Cayman, and I did a total of eight guided dives over two days. Very relaxed slow pace, led by a DM. According to my computer my SAC rate varied between 0.37 and 0.39 cu ft per min.

Last weekend I was back in BVI - same me, same water temperature, same gear. I did three dives, but all three dives were solo dives, in much lower visibility waters, hunting lobster. Two dives had moderate current but the last dive had no current at all. For each dive my SAC rate was 0.62 cu ft.

Probably no surprises there (except for the fact that no current on my final dive in the second set didn't reduce the SAC), but interesting when you strip out a lot of the variables to see such a direct correlation in change of SAC rate attributable to a single factor.

In addition to navigation, hunting and current are you accustomed to solo diving?