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So, I've been diving for a couple of years and have logged 72 dives. ....
My SAC averages pretty good at 10l/m or 0.35l/m but to reach that I have to consciously relax

One thing I did recently was buy a Perdix AI, which has a real time SAC rate in BAR (or perhaps PSI for my North American friends ... but BAR's easier because you just multiply SAC Rate in BAR by Tank Capacity Litres to get to Litre per minute). I hesitated buying it, because I was worried that I would stare at it all the time, but it has helped lower my my SAC rate by 40%. In the course of a couple of months.

I'm not certain you need to have SAC rate below 10L/min, to do tech diving. Certainly I don't. I just came back from the Maldives and a couple of the instructors there have 7l/min SAC's they hop out of the water and have a cigarette. So it has nothing to do with respiratory fitness, despite what people say. Buy a rebreather and it won't matter, because they really do measure respiratory fitness.
 
I just came back from the Maldives and a couple of the instructors there have 7l/min SAC's they hop out of the water and have a cigarette. So it has nothing to do with respiratory fitness, despite what people say. Buy a rebreather and it won't matter, because they really do measure respiratory fitness.

Id like to see what happens when they have to do some exertion (strong current, helping an incapacitated buddy, etc).

Rebreather isn’t a magic carpet. If your sac rate is high you’ll quickly run into bailout limits. Same thing apples as above regarding exertion, too. Low Co2 exchange in an inherently high WOB environment will be exacerbated by smoking.
 
Breathe in:
1-2-3

Breathe out:
1-2-3-4

I generally keep the same number of counts, but the duration of each beat might change. In still open water at a leisurely pace, I might only have 6-7 breaths per minute. Swimming upstream into current, I'll breathe more frequently as needed to support the exertion.
 
Rebreather isn’t a magic carpet. If your sac rate is high you’ll quickly run into bailout limits.

Yes I understand what you are saying about being bailout constrained on a Rebreather, but the original poster say he want to get into teck too.

I just question how easy is it to guestimate your SAC rate in a bailout scenario. - if you bail out because of a Co2 hit its going to be hard to maintain a low SAC rate. Your going to be stressed and SAC is going to be MUCH MUCH higher than the avg 18l/min

So the safe option Dive your rebreather with a BIGGER bail out tank.
 
Low Co2 exchange in an inherently high WOB environment will be exacerbated by smoking.

Yes I agree, I wasn't promoting smoking and diving, more putting it out there how surprised I was to see instructors smoking, also surprised that they had 7 L SAC's. It seems rationally sub-optimal to me.
 
Breathing is just like sex, in-out-repeat as needed.
 
I never frog kick, I consider this an obsolete technique, after the horizontal scissor kick was invented, approximately 20 years ago. This works better with long freediving fins, while frog kicking requires shorter and rigid blades...
But we are going off topic here, breathing technique has little connection with kicking (apart going to dyspnea if kicking inefficiently, which was my point).
Frog kick is used extensively in technical diving, along with shorter more rigid blades.
 
@Angelo Farina is horizontal scissor kick the one where you turn sideways and close the legs one fin on the top of each other ?
 
@Angelo Farina is horizontal scissor kick the one where you turn sideways and close the legs one fin on the top of each other ?
NO. The body stays horizontal, and legs are opened by keeping them perfectly straight. The left leg goes to left, the right leg goes to right, perfectly extended, without flexing knees or ankles.

I need to find a video of my wife using it. I did not find any video on youtube showing it...
The opening movement is like a dancer, but a dancer opens her legs much more (180 degrees instead of 90):

manifestazione-della-ballerina-spaccata-sul-pavimento-dello-studio-92042239.jpg
 
Frog kick is used extensively in technical diving, along with shorter more rigid blades.
I know. Very good for avoiding to raise mud and silt from the bottom, as legs and fins are kept well above the body.
Unfortunately this kick is very disruptive for the red coral inside the caves of Capo Caccia, so it is substantially forbidden there.
Also the rear-mounted cylinder is better avoided inside these caves, often it was required to move the cylinder in front, pushing it with hands along the tunnel, or to use side mount.
In some passages, it was recommended to proceed face-up: this way you better see the coral, and you avoid hitting it with parts of your body or equipment.
I love those caverns, truly spectacular, and not so dangerous as, for example, capo Palinuro, where many lives were lost.
 
https://www.shearwater.com/products/swift/

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