SAC, temp and diving wet vs dry

[Packhorse]

I know (think) that generaly diving dry will increase your SAC, and that colder water temps will increase your SAC when diving wet, but at what temp point (if any) will your SAC be lower when diving dry vs wet?

 

[Meng_Tze]

I know (think) that generaly diving dry will increase your SAC, and that colder water temps will increase your SAC when diving wet, but at what temp point (if any) will your SAC be lower when diving dry vs wet?

Temperature increased (or any increased RMV/DCR) is a personal thing. It is difficult to determine at what temperature, kind of suit each person would increase/decrease this.

But there are some pointers: temperature, work load, stress level, 'last time in the water', currents etc.

My consumption rate is usually lower when I am well rested and not too warm. I prefer to be slightly cool.

 

[Rick Inman]

I don't think it's water temperature, but rather body temperature. The right amount and correct insulation should keep your body warm regardless of the water temp. However, adding insulation means adding bulk which could increase your sac.


It's also just getting used to change. When I first went to doubles my sac went way up. Then, as I adjusted and I realized how to use the extra mass to my advantage, it came back down.

My sac rate does not go noticeably up in the dead of winter (water temp in the 30's), but does when I make an impacting equipment change, just until I get used to it.

YMMV

 

[fire_diver]

I agree with Rick. I think it's the diver's internal temp that affects SAC. And sometimes the SAC changes when no reason is apparent. Take this weekend for example. I was diving my 7mm with a hood, just like I normally do. I was diving in a known location I have dove many times. My normal SAC is in the .4s. Saturday I hit .25 for my dive. I don't know why it dropped. All I know is that I was using a rented tank of Nitrox, and I wasn't about to end my dive with over 1000 PSI. So I just kept swimming around, looking at the plane and playing with the perch and catfish that trailed me like puppies. Of course maybe that was it. I wasn't thinking about anything but having fun for as long as possible.

FD