Twin cylinders??

[Schwob]

On SB low air consumption is treated as if a proxy for penis size.

Wait, which way does this go? So if I at this point were to care more about my consumption than the other, would I need to look at a reduction or an enlargement to improve my consumption???

 

[EricTheDood]

Different situations have different "best" solutions. Slinging an AL30/40 stage bottle might not give you the best results, but will generally work in every situation.

1. It's your own rig and you travel with it, so you always have it.
   
   
2. You fill it yourself with a transfer whip (which you also own and travel with)
   
   
3. Dive ops are unlikely to object to you slinging an AL30/40.
   
   
4. More backgas doesn't help if all your buddies are also running larger cylinders.
   
   
5. You can get in and out of the water just like the other divers running backmount singles. No funny stares or special requests required.

Using a slung botle as a stage bottle requires some planning that you'll need to figure out for yourself. You wouldn't be using it as a "pony", which is a term reserved for emergency-only usage. You'll also need to figure out how you'd fill your stage bottle between dives.

 

[JamesBon92007]

I'm guilty of not reading all the posts so please excuse if this is a repeat...

Have you tried Nitrox? I know very little about it however I dove with a woman who used one 50 cu/ft tank of Nitrox to everyone else's two AL80s of air. She is no bigger than a minute and probably around 80 years old and has been diving since the 50s and must have little bitty frog lungs but still, it was impressive.

Other than than, a bigger tank and more experience as I'm sure others have pointed out.

 

[decompression]

If I may, contact Chad Whitman, My Bio, he offers an extreme scuba makeover, guaranteed to get some lead off your belt, make you feel more relaxed under water and get your SAC down. Not a bad return for a few hours in a pool.

 

[Kenmx10]

This may help. Practice breathing in your bed when you can hear yourself breath. Slowly breath in for 3 seconds. taking in small breaths. Hold it for 3 seconds. Then slowly exhale for 3 seconds. Hold your breath for three seconds , then slowly take another breath. Keep doing this till your comfortable and develop a rhythm and it becomes natural. Once you've trained yourself to do this, when you get in the water you will be able to hear yourself breath and you will notice right away if you are sucking down air too fast. Ive seen people take a breath in one second and blow it out the next second, so in a minutes time they have taken 30 breathes of air(just wasting air). And many times people that do this take in large breaths at a time. So if you are taking 1 breath every 3 seconds , you are only taking 8 to 10 breaths per minute. As opposed to 30. I usually try to shoot for 6 seconds. This will also help you be more relaxed in the water. And generally speaking, the more relaxed you are , the better the dive will be.

Also , watch some youtube videos of some professional divers and listen when they breath in and when they breath out and practice imitating their breathing patterns while watching the video (notice that they breath in slow and exhale slow). These exercises will help conserve air. Like a musician using a metronome for timing.

Also, some divers use a lot of air at the surface before they actually start their Dive. Either while waiting for their buddies or swimming around to the front of the boat to grab the anchor line. Or both. I will usually spit out my regulator after I hit the water and not put it back in my mouth till I start to descend. Sometimes I even forget to put it in back in till I'm already 5 to 10 feet down (I Blame it on free diving).

Ive always thought that since you are taking 20 less breaths per minute , you are taking in that much less nitrogen. But have no scientific data to support that and am not suggesting that. I know your scuba instructor will tell you never hold you breath, so that you don't start your ascent and cause lung over expand. So, I would suggest breathing at a normal rate while ascending. Ive learned this from watching tons of Videos of experienced divers taking a breath anywhere between 5 to 10 seconds apart and it worked for me. If it doesn't sound right to you or doesn't feel right , ignore all of the above.

 

[KenGordon]

This may help. Practice breathing in your bed when you can hear yourself breath. Slowly breath in for 3 seconds. taking in small breaths. Hold it for 3 seconds. Then slowly exhale for 3 seconds. Hold your breath for three seconds , then slowly take another breath. Keep doing this till your comfortable and develop a rhythm and it becomes natural. Once you've trained yourself to do this, when you get in the water you will be able to hear yourself breath and you will notice right away if you are sucking down air too fast. Ive seen people take a breath in one second and blow it out the next second, so in a minutes time they have taken 30 breathes of air(just wasting air). And many times people that do this take in large breaths at a time. So if you are taking 1 breath every 3 seconds , you are only taking 8 to 10 breaths per minute. As opposed to 30. I usually try to shoot for 6 seconds. This will also help you be more relaxed in the water. And generally speaking, the more relaxed you are , the better the dive will be.

Also , watch some youtube videos of some professional divers and listen when they breath in and when they breath out and practice imitating their breathing patterns while watching the video (notice that they breath in slow and exhale slow). These exercises will help conserve air. Like a musician using a metronome for timing.

Also, some divers use a lot of air at the surface before they actually start their Dive. Either while waiting for their buddies or swimming around to the front of the boat to grab the anchor line. Or both. I will usually spit out my regulator after I hit the water and not put it back in my mouth till I start to descend. Sometimes I even forget to put it in back in till I'm already 5 to 10 feet down (I Blame it on free diving).

Ive always thought that since you are taking 20 less breaths per minute , you are taking in that much less nitrogen. But have no scientific data to support that and am not suggesting that. I know your scuba instructor will tell you never hold you breath, so that you don't start your ascent and cause lung over expand. So, I would suggest breathing at a normal rate while ascending. Ive learned this from watching tons of Videos of experienced divers taking a breath anywhere between 5 to 10 seconds apart and it worked for me. If it doesn't sound right to you or doesn't feel right , ignore all of the above.

Kenmx10,

Consciously trying to breath less is not always a good idea. Being aware of your breathing and avoiding excessive breathing is fine, but breathing is about getting rid of CO2. Skip breathing and other schemes to reduce air consumption by breathing less or more shallowly can lead to CO2 build up. That increases the urge to breath, leads to narcosis, greater susceptiblity to oxygen toxicity, headaches and anxiety.

Eaten at relatively shallow 'recreational' depths the gas density starts to make gas exchange difficult. Add in breathing poorly and co2 build up is easier than you might think.

Watch for a proper view of this stuff.

Regarding not breathing your gas at the surface. That is fine if diving a mill pond. In the sea with waves it is not such a good plan. Better advice might be to always be last in. In any case the rate of gas use at the surface is a fraction of that on the dive. You may think it is the height of coolness to dump your bcd and start to descent without a regulator in your mouth, but actually you are taking a leap into the unknown. All that time you have not been breathing your regulator as your buddy does their think is an opportunity for undetected failure. Once you have dumped your bcd and started to descend is not the time to discover something going pop, a partially closed valve or whatever new and interesting failure will get you.

Your last paragraph is a bit scary with respect to nitrogen take up.

 

[Kenmx10]

Kenmx10,

Consciously trying to breath less is not always a good idea. Being aware of your breathing and avoiding excessive breathing is fine, but breathing is about getting rid of CO2. Skip breathing and other schemes to reduce air consumption by breathing less or more shallowly can lead to CO2 build up. That increases the urge to breath, leads to narcosis, greater susceptiblity to oxygen toxicity, headaches and anxiety.

Eaten at relatively shallow 'recreational' depths the gas density starts to make gas exchange difficult. Add in breathing poorly and co2 build up is easier than you might think.

Watch for a proper view of this stuff.

Regarding not breathing your gas at the surface. That is fine if diving a mill pond. In the sea with waves it is not such a good plan. Better advice might be to always be last in. In any case the rate of gas use at the surface is a fraction of that on the dive. to dump your bcd and start to descent without a regulator in your mouth, but actually you are taking a leap into the unknown. All that time you have not been breathing your regulator as your buddy does their think is an opportunity for undetected failure. Once you have dumped your bcd and started to descend is not the time to discover something going pop, a partially closed valve or whatever new and interesting failure will get you.

Your last paragraph is a bit scary with respect to nitrogen take up.

Not sure what is scary about the last paragraph? As long as you dive within your limits or follow your computer, like most people do these days, Nitrogen intake will be calculated exactly the same. No matter if you are taking 60 breaths per minute or 20. The thought that someone is controlling their breathing and not blowing off air too quick has nothing to do with Dive limits , RNT, or NDL.

"You may think it is the height of coolness"-uncool

 

[KenGordon]

Ive always thought that since you are taking 20 less breaths per minute , you are taking in that much less nitrogen

This shouts 'I have no clue'.

 

[KenGordon]

"You may think it is the height of coolness"-uncool

Let me be clear, descending without a regulator in your mouth is a stupid thing to do.

 

[stepfen]

Hello,

I am in a similar situation with the OP. Relatively new diver, big (1.9m, 100kg), not particularly fit with SAC rate of about 18-20lt/min. It has improved quite a bit (I started with ~25lt/min) but still it is high.

Recently I did some rec dives with another much more experienced diver. He was big and not very fit and he had high gas consumption too.

He was diving with twins (I think 10 or 12lt) and BP&W plus a 12lt “stage” as he called it. For the two daily dives he used most of the gas in the twins plus some of his “stage” air.

Looking at him I liked the “stage” idea for me too (I’d personally leave the twins/BP&W setup for later).

Is it possible to dive with single 12lt AL tank on a usual jacket BCD and a 12lt “stage”??? Once I reach 50bars or so in my main tank I’d switch to the stage until the end of the dive. For the second dive I’d use a new 12lt main tank plus the remaining air from the first dive in the stage. Is that setup possible / recommended and if so what training is needed?

For me that would have several benefits. The main one is to have an extra independent gas supply. More than that I'd have more than enough air for my dives and "carrying" the stage didn’t look particularly uncomfortable at all. It also looks a good step towards more advanced setups and I’d guess practically it shouldn’t be that difficult to rent a stage in most places for a small extra cost.

Any recommendations welcome.
Thanks a lot