How to reduce a monstrous SAC

[beaverdivers]

If you use an Air-Integrated dive computer with a heart rate monitor on every dive like we do with our students, then you can download your computer after every dive and analyze your breathing, heart rate and workload.

The Scubapro Galileo Sol is the computer that we use to train ALL of our students.
It is amazing to watch students progress using this method.

Last night we had a refresher student about your built go from 1.36 cuft/min to .6 cuft/min. in one three hour pool session!

Both the breathing speedometer and the heart rate profile enables you to get biofeedback on your dive at a sample rate of every 4 sec.

Moreover, you can see what your workload % is based on your heart rate or your breathing rate!

Also, I would recommend that you dive with two independant tanks, 2 80 cuft or 2 63 cuft. tanks. That way you will not be "the Guy" that is low on nitrox and is the first to end the dive.

By having two independent systems, you'll have redundancy.

Make sense?

 

[Bubbletrubble]

I couldn't disagree more with what beaverdivers wrote.

Following that advice will result in the purchase of a lot of unnecessary, expensive dive gear.
It might also result in CO2 retention.

 

[Centrals]

I couldn't disagree more with what beaverdivers wrote.

Following that advice will result in the purchase of a lot of unnecessary, expensive dive gear.
It might also result in CO2 retention.

Absolutely brilliant.

 

[Charlie99]

Lots of good advice above. My additional tidbit it to try and stay neutrally buoyant throughout the dive. The simple test for this is to stop swimming and see if you maintain the same depth.

Many divers unknowingly go around negatively buoyant, continuously finning to maintain depth.

When all is said and done, your SAC is what it is. Embrace it. Enjoy your dives.

Charlie

 

[lowviz]

.....//.....stop swimming and see if you maintain the same depth. ....//....

And trim. If you can do this for one minute, any good instructor can teach you anything.

 

[Hatul]

The style of diving also makes a big difference in SAC. There are swimmers and there are hoverers. My own SAC can vary on the type of dive: on a hover dive my SAC is 0.55 cu.ft/min and jumps to 0.75 in a swimming dive. Since you're an athletic guy you may be moving more than most and that will raise your ventilation.

 

[Bogie]

You are a big guy with big muscle mass and big lungs. You can't compare your SAC rate with smaller people. Women tend to have great SAC rates. It depends on each person. Relax, move slow and easy. Good buoyancy is a must because diving becomes effortless when you are relaxed with good trim and buoyancy. Do a test dive where you just relax and stay still. My trick is try to fall asleep you are so relaxed. You will notice that you will get colder because you're not moving but this should give you a base line how low you can get your SAC rate.

Have fun!

 

[beaverdivers]

Following that advice will result in the purchase of a lot of unnecessary, expensive dive gear.

If you figure your cost /min of Bottom Time, the Galileo Sol will pay for itself in a short time.

Furthermore, due to the fact that you are getting rid of the High Pressure hose(s) you are more streamline.

You can have transmitters on each independent first stages, so that you eliminate all the hoses and drag.

REMEMBER you are trying to be as steamlined as possible!

If it were just about the money, I guess some people would want us to all drive VW beetles.

We do not SCUBA dive to save money. We SCUBA dive to have FUN. If you are the one that has run out of FUN tickets ( nitrox ), are you having as much FUN as you could!

You are TOO big to fit in a beetle.

 

[drrich2]

Just wanted to add a bit on being careful of CO2 retention. I'm early 40's, about 6'1", 275 lbs, kind of a semi-sedentary sort, not in great shape. Diving in the Caribbean, my SAC is around 0.75 (varies either way).

On a 2 tank boat dive trip one day on a cruise stop in Grand Cayman, I used skip breathing (which people hear warn you against) on the first dive, to extend my bottom time. It did help somewhat. It also left me with a headache so intense I almost called the 2'nd dive (thankfully it eased off enough over the surface interval so I didn't miss what was a fine dive!).

Years ago in professional training, the first time I entered an operating room to observe (note: I am NOT a surgeon!!!), I watched a feeding tube placement. Got sleepy, sort of swaying back & forth on my feet. I was really embarrassed thinking I was just inexplicably sleepy. My vision started losing focus. The Physician doing the surgery explained that I was rebreathing CO2 because of the mask over my face, & had me go sit against a wall without the mask. Soon, both my hands/forearms felt like I was holding one of those vibrating aerators people used to use to blow bubbles in fish aquariums. Very distinctive experience.

My point is, while I applaud a serious effort to enhance air efficiency and extend bottom time, be careful. I think some of this stuff can slip up on you if you're not careful. You don't want to stay down the rest of your life...

Richard.

 

[TSandM]

Furthermore, due to the fact that you are getting rid of the High Pressure hose(s) you are more streamline.

You know, I'll buy this just a little bit with regulator hoses, which tend to loop out away from the diver and sit in the water where they cause some drag. But the HP hose routes downward, along the diver's body, and perhaps up under the arm to be clipped off on a d-ring if the diver has a console he wants to secure that way. I don't think HP hoses cause any significant drag at all, unless they are ridiculously too long.