Is my air consumption...bad-ish?

[anchochile]

My SAC rate ranges from around 0.45-0.50 cuft/m on a relaxing warm drift dive to about 0.55 or 0.6 when I have to work harder. I'm male, on the smaller side, not too much fat or muscle. I usually get placed in groups with more advanced divers because my buoyancy and trim are pretty solid (or so DMs tend to tell me - it doesn't always feel that way!).

When I'm diving a cattle boat with lots of once-a-year vacation divers, I have plenty of air - I'm often back on the boat with 1000 PSI or more in a scenario where the whole group goes up together.

But when it's an option, I tend to pick operators who cater to more advanced divers, and I've noticed that when in groups with advanced divers, I tend to be the first one to hit my reserve pressure, even when my SAC rate is around 0.45cuft/m.

I know there are threads going on and on about how it doesn't matter what is "average" air consumption, personal physiology plays a huge role, etc. I get it - I don't have anything to prove, and I'll breathe how I breathe. But I'm still curious - is 0.45 or 0.5 cuft/m a "high" air consumption rate for most advanced divers? If this is my air consumption, should I expect that I will often be the limiting factor, and perhaps should spring for bigger tanks when traveling so that I'm not cutting everyone else's dive short? Or have I just been paired with some ridiculously light breathers on recent trips?

 

[victorzamora]

No, 0.50cuft/min is a pretty good SAC rate. It's nothing earth-shattering, but it's good. I'd say that most cave/tech divers I know are above that.

 

[Marie13]

Mine is around .6, but that’s doubles and drysuit in cold water.

 

[anchochile]

No, 0.50cuft/min is a pretty good SAC rate. It's nothing earth-shattering, but it's good. I'd say that most cave/tech divers I know are above that.

Yeah, that's what I've always figured - that I'm in the totally solid but not amazing range. I guess my faith in myself was shaken today in Cozumel when I hit reserve pressure first, sent up my SMB and did a safety stop solo, and was back on the boat with 500 PSI where I waited a full 10 minutes for the other 6 divers in my group to surface. I was like, wait, am I the air hog??? Downloaded the dives to Subsurface tonight, and yep, SAC was right at 0.47 cuft/m for that dive.

 

[anchochile]

Mine is around .6, but that’s doubles and drysuit in cold water.

Yeah, my figures above are all warm water fun-time diving. In cold water (wetsuit) I'm around 0.55-0.6 when relaxed.

 

[kmarks]

I think you've just been unlucky enough to be on the wrong boats. Were all the other divers always in-shape, experienced women divers? I've been out breathed by 12 year old girls with fewer than five dives. We just can't compete.

I'm usually asking the last to get back on the boat, but I don't think my SAC is that different than yours. Drift diving in Cozumel, my computer calculates my SAC around 0.35-0.4 and in cold water where I actually have to work to get around (Catalina in December), I'm about 0.5. I'm male, in my late thirties, and in very good shape.

 

[AdivingBel]

Using your Coz example, how long were your dives? Depth is certainly a big factor, but typical Coz dive profiles are pretty well known. I would say if you can make 50 min on your typically deeper 1st dive and a bit closer to 60 min on your 2nd dive (assuming you're not hitting NDLs), then don't worry about it. If not, try the larger tank and/or go with an op that doesn't care if you surface on your own on your own bag. No harm, no foul. Enjoy the extra time on the boat chatting with the DMs and boat captains. Most of all relax and have fun. Worry over SAC is counter productive. All IMHO, YMMV.

 

[Steve_C]

Are you diving the same tanks as others? In NC many divers dive HP100s, myself included, and I have dove with divers diving 120s. If you are diving AL-80s (which are not even 80) you will have less air.

 

[GreggS]

I usually have a SAC of between..43 and .52 depending on conditions, which is much better than when I first started. I'm 6' tall and weigh around 240. My 5'3" 130 lb wife has a rate between .25 and .30 and has since she began diving.

I see you are between 50-99 dives so you can probably improve some more on your air consumption. But don't fret over it if you don't. You're already in a pretty good spot.

 

[GJC]

I average around 0.5.

I got 0.36 once, but that was just staying in 1 spot with no current. That dive wasn't much fun.

One thing you can do to beat the other divers is to stay slightly higher than them. If you hug the bottom and are the lowest diver during the entire dive, your total air use will be higher, even if your SAC is actually a little lower than everyone else.