Huge air consumption even after +200 dives

[Tycksel]

I'm a 193cm/120kg 40y guy and working as a divemaster. I have around 250 dives logged and the problem is my air consumption: SAC rate is around 21-24l/min.

My gear is working good and trim/finning technique and buoyancy is ok. Weights are as low they can be so I can stay on safety stop and I move slow. Breathing pattern underwater is around 4 sec in, 6-8 sec out.

I'm almost always first who runs out of air, which is really annoying when I'm diving with customers. I use 12L alu tank and we don't have bigger tanks in our dive center. Also diving with sidemount is not allowed when leading customers.

What could I do to reduce my air consumption? Of course some kind of cardio probably would help, but I just love to go to gym 4-5x/week more than that. But no one in our dive center does any cardio (+most of the guys smoke and drink a lot) and they still have great air consumption.

 

[davehicks]

Have somebody shoot video of you diving, especially when you don't know they are shooting. Are you finning a lot? Using hands? You say your buoyancy is just "OK", which makes me suspect. Are you horizontal when floating or swimming or do you have a vertical slant?

Try being more focused on breathing. Do a 5 count during inhale, pause, 5 count on exhale.

Are you cold on these dives? Do you have a sufficient suit or layers for multiple dives a day?

 

[Tycksel]

Have somebody shoot video of you diving, especially when you don't know they are shooting. Are you finning a lot? Using hands? You say your buoyancy is just "OK", which makes me suspect. Are you horizontal when floating or swimming or do you have a vertical slant?

Try being more focused on breathing. Do a 5 count during inhale, pause, 5 count on exhale.

Are you cold on these dives? Do you have a sufficient suit or layers for multiple dives a day?

Yeah they have filmed me many times. My trim is totally horizontal and I'm also diving with wing, so that makes horizontal trim quite easy. Not using hands at all when I dive. I usually kick, glide for 5 seconds and then they still for around 5 seconds.

I always go up a little when I inhale and go down a little when I exhale, so that's why I think that my buoyancy is just ok.

I'm using 3mm vest with hood and 3mm full wetsuit. Water temperature is 28-29c. I'm quite happy with that and don't feel cold.

 

[scubadada]

Hi @Tycksel

It's difficult to offer easy advice to improve your gas consumption. You have already answered the additional questions I had. Where are you diving in the warm water, must not be at home in Finland? I assume you are frog kicking. I also assume you are relaxed while diving.

Other than fine tuning your breathing with a brief pause after inhaling, I can't think of anything obvious. Your gas consumption may largely be set by your body size. You may simply need to figure out how to get a larger cylinder.

 

[GF99/99]

I'm a 193cm/120kg 40y guy and working as a divemaster. I have around 250 dives logged and the problem is my air consumption: SAC rate is around 21-24l/min.

My gear is working good and trim/finning technique and buoyancy is ok. Weights are as low they can be so I can stay on safety stop and I move slow. Breathing pattern underwater is around 4 sec in, 6-8 sec out.

I'm almost always first who runs out of air, which is really annoying when I'm diving with customers. I use 12L alu tank and we don't have bigger tanks in our dive center. Also diving with sidemount is not allowed when leading customers.

What could I do to reduce my air consumption? Of course some kind of cardio probably would help, but I just love to go to gym 4-5x/week more than that. But no one in our dive center does any cardio (+most of the guys smoke and drink a lot) and they still have great air consumption.

21-24 l/min sac rate sounds pretty normal for a dude that is 193cm and 120kg. Not to sound rude but your a big guy with large lungs and alot of body mass for your lungs so oxygenate. Honestly I would say 18-20l/min for someone your size is the lower end so your not far off.

I would not stress to much about it, if you really practice breather work and really focus on it during the dive you might get down to 20l/min but when you hear people braging about there 8l/min sac rates they are generally very small framed people (yeah I'm sure someone will chime in about a big guys with low sac rates but that is not the normal)

Very strange they do not let you dive sidemount... What about with a stage, you could always carry an s40 travel gas.

 

[Pbdiver84]

You are 120 kilos. Everything else being equal, you will go through air much faster than someone 80kg or even 50kg.

Having said that, based on going up and down with breathing, I’m guessing you are taking much bigger breathes than you need to if you are totally relaxed.

 

[Underwater Tourist]

Also, you shouldnt really have a goal to reduce your sac to begin with.

Good sac rate is a result of good technique and efficiency in the water, so thats what you should focus on, and then sac rate will fall into place and you will reach your personal good sac rate. For everybody its a different number.

If you know you are good and efficient in the water and your sac rate is still "high" thats just what it is naturally for you. There is absolutely no benefit in trying to artificially push it lower nor that it is something that is "bad". It is what it is

I am 190cm and 80kg and have sac of 14-15l/min, some might say it could be improved, but that what it turns out to be naturally when i do the dives i like, move around as much as i like

this might be a fun poll for you to see: Average Gas Consumption

 

[Tycksel]

Also, you shouldnt really have a goal to reduce your sac to begin with.

Good sac rate is a result of good technique and efficiency in the water, so thats what you should focus on, and then sac rate will fall into place and you will reach your personal good sac rate. For everybody its a different number.

If you know you are good and efficient in the water and your sac rate is still "high" thats just what it is naturally for you. There is absolutely no benefit in trying to artificially push it lower nor that it is something that is "bad". It is what it is

I am 190cm and 80kg and have sac of 14-15l/min, some might say it could be improved, but that what it turns out to be naturally when i do the dives i like, move around as much as i like

this might be a fun poll for you to see: Average Gas Consumption

You have point here. My best SAC rates has been last winter (around 15-17L/min) when I was mostly fun diving and didn't focus on my breathing. Just looking for fishes and taking videos. Now I tend to use more air when I'm leading, even though my breath technique is almost same

Hi @Tycksel

It's difficult to offer easy advice to improve your gas consumption. You have already answered the additional questions I had. Where are you diving in the warm water, must not be at home in Finland? I assume you are frog kicking. I also assume you are relaxed while diving.

Other than fine tuning your breathing with a brief pause after inhaling, I can't think of anything obvious. Your gas consumption may largely be set by your body size. You may simply need to figure out how to get a larger cylinder.

I dive in south east Asia, mostly in Thailand. And yeah frog kicking

 

[johndiver999]

Perhaps get a 30 cuft pony bottle, back mount it and use half of it at the start or middle of the dive to give yourself more time on the 80 ?

Obviously it might be less complicated to give the 250-lb man a tank larger than an 80, but if that is not an option.

 

[LI-er]

Of course some kind of cardio probably would help, but I just love to go to gym 4-5x/week more than that.

What does this even mean? Do you go to the gym more than 5x per week or are you being sarcastic and you don't do any exercise? What's your level of fitness in general? Can you hike up a mountain, or a few flights of stairs without getting winded? The high air consumption is a symptom of a BIGGER problem, you are obese according to the charts and that will lead to more serious problems than rapidly draining a tank.

Perhaps get a 30 cuft pony bottle, back mount it and use half of it at the start or middle of the dive to give yourself more time on the 80 ?

This is a really good idea but realize it's just dealing with the symptoms not the underlying problem.