Advice to get lower SAC?

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Can anyone suggest any tips to get a lower SAC?

Don't know if this was mentioned already, but learn to diaphragm breath.

The exercise: Lay on your back. Place a 3 to 5 pound dive weight on your chest, centered between the nipples. Practice breathing without letting the weight move up or down. Make that a memory reflex and use this breathing technique while you are diving. It should lower your SAC noticeably unless you were already doing this to begin with. SAC reductions of around 25% are common.

PS - Another good option is to take some freediving classes. A big chunk of the class will be about learning to breath efficiently. You need to learn a lot about breathing before you learn how to not breath.

PPS - Invoke the "Dive Reflex" before you go scuba diving. It will release PH buffers into your bloodstream that will relax your body toward the acidity of CO2. That acidity will tend to make you breath more heavily, the buffers will suppress that. You will learn about this in a freediving course.
 
This thread is 4 pages long and you haven't gotten any suggestions as to how to lower your SAC rate? I didn't read the responses but I'll give you several methods to do exactly that.

- Dive. The more you dive, the more you will relax, the more efficiently you will move through the water and the less energy and therefore gas you will use
- Streamline your gear. The less drag, the greater the efficiency, and the less effort. That means less gas consumption.
- Improve your physical fitness. That means less effort to do more strenuous activities. A slimmer diver isn't dragging a whole bunch of blubber through the water or working up a sweat and heavy breathing when preparing for the dive, whether it's a jump off a boat or wading out from shore.
- Don't smoke- it decreases lung efficacy which means more wasted gas with each inhalation.
- Move slowly through the water. The faster you go, the more drag, that means more energy expended and more gas consumed.
- Don't use your arms to swim, learn which fin kicks are most effective for particular diving conditions, because using arms isn't efficient which means wasted energy and efficient kicks can be a huge energy and gas saver
- Improve your trim and buoyancy so you won't be doing a whole bunch of micromovements to stay level and compensate for unwanted changes in depth.
- Learn to use the minimum amount of weight. That means you're dragging less weight through the water and less air in your BCD means less drag as well.
- Learn relaxation and slow breathing techniques such as taught in yoga and mediation
- Learn techniques that will require less effort for specific dive conditions. Such as pulling along the edge of a shipwreck rather than free swimming against a current that is running along the wreck, or finding eddys in the current by ducking in between patches of reef or under ledges rather than working against a current.

So there's a whole bunch of ways to improve your SAC rate. You're welcome.


thanks!

reading through this, I am already doing the great majority of this.

I am very relaxed in the water. I have spent my entire life in and around water.
I have streamlined my gear as much as possible at this point.
I could certainly be in better physical shape, but I am not in bad or poor shape either.
Smoking. No thanks.
I already use slow and deliberate movements in the water.
I do not use my arms at all. they generally stay as close to my body as possible.
My buoyancy and trim are pretty good, at least I believe so.
I practice some breathing techniques just before going down. It drives my dive buddy nuts cause hes excited in a hurry to get under, and I make him sit at the surface a few minutes while I spend some time focusing on myself, and going a bit "inward" in order to get myself in the right mindset, and relaxed and get my breathing as low as I can before going down.
I have my weights dialed in pretty well. I think 1-2 pounds less and I wouldnt be able to get down.
That last part comes with experience I think. Most of my diving is in the Great Lakes which have very little bottom current.


Thanks for taking the time to put this list together!
 
Don't know if this was mentioned already, but learn to diaphragm breath.

The exercise: Lay on your back. Place a 3 to 5 pound dive weight on your chest, centered between the nipples. Practice breathing without letting the weight move up or down. Make that a memory reflex and use this breathing technique while you are diving. It should lower your SAC noticeably unless you were already doing this to begin with. SAC reductions of around 25% are common.

PS - Another good option is to take some freediving classes. A big chunk of the class will be about learning to breath efficiently. You need to learn a lot about breathing before you learn how to not breath.

PPS - Invoke the "Dive Reflex" before you go scuba diving. It will release PH buffers into your bloodstream that will relax your body toward the acidity of CO2. That acidity will tend to make you breath more heavily, the buffers will suppress that. You will learn about this in a freediving course.


This has not been mentioned before. I will give it a try. Thanks!
 
Rhythmic diaphragm breathing may also help you lower your SAC rate. It's also healthier as it cycles more CO2 out of your lungs with each breath cycle.

Focus on drawing gas into your lungs using your diaphragm muscles as opposed to your neck or chest muscles. Then exhaling using your chest. Try to regulate a rhythm so you spend an equal amount of time on inhale as exhale. Start with a four count for each. Do not skip-breathe or pause in between. 4-seconds breathing in, 4 seconds breathing out. Once you find you've fallen into that rhythm with out counting to four in your head, move to five, then six and so on. If you can get down to 4 breaths per minute (7-8 seconds on inhalation and exhalation with no holding/skipping) you're going to see a big difference in your overall gas consumption.

You can also 'see' this in other divers. Look at their bubble stream. Do they emit bubbles for the same amount of time as they're not? Or do they breathe in slowly and exhale hard and fast?
 
Years ago a friend/instructor told me to hum. I did. Drove my buddies crazy but it worked. Sometimes I still hum but luckily for all, it’s in my head now!!!
 
Rhythmic diaphragm breathing may also help you lower your SAC rate. It's also healthier as it cycles more CO2 out of your lungs with each breath cycle.

Focus on drawing gas into your lungs using your diaphragm muscles as opposed to your neck or chest muscles. Then exhaling using your chest. Try to regulate a rhythm so you spend an equal amount of time on inhale as exhale. Start with a four count for each. Do not skip-breathe or pause in between. 4-seconds breathing in, 4 seconds breathing out. Once you find you've fallen into that rhythm with out counting to four in your head, move to five, then six and so on. If you can get down to 4 breaths per minute (7-8 seconds on inhalation and exhalation with no holding/skipping) you're going to see a big difference in your overall gas consumption.

You can also 'see' this in other divers. Look at their bubble stream. Do they emit bubbles for the same amount of time as they're not? Or do they breathe in slowly and exhale hard and fast?

This is the technique I use, and it works well. Just a couple of minor comments, though. With diaphragmatic breathing (at least how I was taught and how I've done it for a few decades) you not only breathe in with your diaphragm but also breathe out with your diaphragm. The chest or "top of your lungs" are not directly used - but if you find it difficult to exhale using your diaphragm, it's not a huge deal exhaling with the top of your chest. It can be just a bit less efficient as you may not be exhaling all of the air in your lungs. And regarding breathing counts, some folks find it easier to maintain their buoyancy if they breath out one count more than then they breath in, so that you don't find yourself floating up. But that's something you can tailor to your own breathing pattern and changes in buoyancy you experience as you breath with this technique.
 
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?
It is possible that you are close to the best you will be able to do. That is not to say that you shouldn't continue to work on controlled - deep, regular - breathing, that you should not continue to streamline, to work on trim, or that you shouldn't move to a frog kick if you haven't already. Free dive training is useful for scuba divers as well.

But, some divers simply consume more air than others. It is not necessarily a function of body size, or fitness, either. It is what it is.

I have been diving 'a while'. I have done a few dives. I have proper weighting, good trim (based on video analysis), and streamlined gear. My 'working' RMV is ~0.7 cfm. My deco RMV is ~0.64. That hasn't changed in 10 years. It is what it is, and I work with it. When my wife (far less dives, fewer years of diving) and I dive in the Caribbean, where we are using AL80s, she routinely uses less air than I do. In fact, we regularly share air (she gives me her long hose for about 10 minutes on each dive) so we end up the dive with equivalent amounts of air (~500 psi) in our cylinders.

For the most part, however, I am in at least the same ballpark as people I dive with. I do dive at times with a few people that seem to hardly use any air at all. So, the disparity between my use and that of a few of my dive buddies is quite substantial. It is possible that you are seeing something similar with the dive buddy you describe. You could be slightly above 'average', he could be slightly below 'average' but the disparity seems large.

Don't stress over it. Use a larger cylinder if you need to (I dive HP 100s), when others are using AL80s. It is not a significant limitation to your development as a diver.
 

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