Advice to get lower SAC?

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Clayton122

Contributor
Messages
169
Reaction score
85
Location
Chicago
# of dives
100 - 199
So I have a regular dive buddy. We dive together often, and at the end of a dive, when I am hitting my return PSI, he still has way more gas than I do.

I have done all the usual crap.

My weights are right. 1-2 less pounds and I couldn't get under. My bouancy is pretty darn good.

My trim is fine. all my stuff is clipped off and I'm as aerodynamic as I can make my rig. None of it is chest restricting too much other than a 7mm wetsuit most of the time. ( cold diving here in the Grreat Lakes )

My movements are slow and deliberate underwater, I do not exert myself needlessly.

Im a fit person in decent shape. Im a tall skinny guy. ( 6'4" 190 pounds )

I breath normally just like I would on the surface. I dont skip breath or anything like that.

My SAC is between 21 and 24. When I have to DMC, its up around 27-30, cause im swiming around a lot.

My dive buddy, his normal SAC on a dive is down near 13-15.


I feel badly because I am always the one who has to end the dive first.

Before going under, I usually take a few minutes on the surface to get my breathing down after all the exertion of getting your crap on as fast as you can cause its 90 outside and a wetsuit is so damn hot.

Can anyone suggest any tips to get a lower SAC? Or based on my description, is this just simply the best I am able to do?
 
My first suggestion, is worry less about your gas consumption.

Trying to bring down gas consumption, often results in poor practice by the diver, e.g. skip breathing.

There are few suggestions I usually make. Ensure you are correctly weighted, streamline and economical in your movements. Often, high gas consumption is a result of constantly adjusting buoyancy, either drysuit or BCD.

The other suggestion is go diving, enjoy it, relax. The more you dive, the more relaxed you get, the better your technique.

Other than this, if your air consumption is higher than your buddies, consider a larger cylinder. This will reduce your stress, and take the pressure off you with regards the point you turn the dive.

Diving with instructors or more experienced divers means you are likely to benefit form tips and tricks. Also errors in your technique will be corrected. Also consider further training, be that technical or recreational (GUE/PADI). Note I said consider, all the training courses in the world won't help if you don't actually go diving. Diver training, generally results in improved technique, and more relaxed diver.

Generally, the more people dive, the better they get, the more improved their gas consumption rate. Every one has a natural level, attempting to get below this is dangerous and fool hardy.
 
-stop smoking
-relax and dive
-take up cycling

- your description of sac is unusable without relating it to cylinder size and average depth. What’s your surface RMV?
 
Years ago the advice I was given to reduce air consumption is to dive dive dive dive dive and dive more. It is about learning to relax. Also, focus on slowing your breathing when you first get it. All the other stuff will help, but not as much as dive dive dive dive dive and dive more. What I mean by this is dive more often in a short period of time.
 
Hi @Clayton122

Not knowing what cylinders you use, I don't know how your SAC translates to your RMV. It does seem like you are on the higher end of the spectrum. From 2 polls on SB, the average RMVs were as below for 339 respondents:
upload_2018-10-23_17-36-40.png

Sounds like you have worked on buoyancy, trim, and effort. Less than 100 dives is not much experience, more diving very well might help you. I find that breathing underwater is different than on land. My average RMV is 0.36 cf/min, I've been diving 48 years, though not continuously
 
Assuming you're diving AL80's, and that's in psi/minute, it's around an RMV of .6 or so on average. So not "great" but also far from terrible. I've found that one of the best things I've done (in my limited experience) to increase my bottom time is to "do less". Kick less, move less, and just overall "do less". Diving for me is more about observing what's there so I try to go slow, drift, and only do something if there's a reason for it.

Also, as mentioned about, don't fret about it. Anything that worries or concerns you on a dive is going to take effort, and air, during that dive. With time you may find it just goes down without thinking about it; I had a RMV of around .7 cuft/min less than a year ago and practice + relaxing already has it down around .5 in good dive conditions, sometimes less.
 
Frogkick: You might play with frog kick, its kick glide rhythm is very efficient for me. At low speed it is super efficient, and I can do a distance covering hurry in it with calmer breathing than with flutter kick. And my fins are sweet but not optimized for frog kick.

Fins: I don't know which ones, but they're your interface to the water.

Streamlined BP/W: your profile pic shows fairly bulging integrated weights up front, BP/W might help. Possibly challenging if you're DMing depending on shop.

Dive.

Two recent threads on RMV:
- Controlling and reducing air consumption
- Breathing
 
Have you tried sneaking some weights into your buddy's gear to even things out?

Only serious suggestion I can add is still speculative. Your photo looks like you might be diving split fins. They are very efficient for a short flutter kick, but a wide scissors kick is wasted energy. Not so sure how they perform if you frog kick, maybe someone else has a thought. Regardless, see if you can try some different fins to experiment.
 
https://www.shearwater.com/products/teric/

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