Huge air consumption even after +200 dives
- Thread starter Tycksel
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Hi @Tycksel
Learning to breathe underwater really isn't easy, is it?
You have more in-water experience than I do, and much more training, so I don't want to say too much. But, a few things come to mind from my own learning experience with breathing from a cylinder...
- How long have you been a professional? If your total dive count is ~250 I'm thinking it's still early in your career. DMs where I am are usually doing at least a couple of tanks every day, at least 5 (sometimes more) days per week (unless it's low season). So depending on how you define "winter" (where I grew up in northern Canada it is arguably six months out of the year, and friends living in Finland tell me it's a similar climate!) that adds up very quickly. I ask this because for me if I am under any stress at all my SAC rate is significantly higher, and it could be that if you are still new to being a divemaster you will find your SAC rate decrease as you gain experience and find it less stressful... If I were a DM right now my gas consumption would be through the roof!
- It probably isn't what dive professionals want to do on their days off, but when you are working in SE Asia do you have opportunity or inclination to do any "fun dives"? Like, where you aren't the one responsible for a group - maybe just a dive with a buddy in conditions similar to what you are diving as a pro. And not that you should spend those dives focusing on your SAC rate, because that will defeat the purpose. Just a dive purely for fun. In that case, what is your SAC rate? If you could measure that you would have a "baseline" for that environment that you could then use for comparison against your "working" SAC rate.
- Gas consumption is (logically enough) not just a matter of breathing rate but also breathing volume. For me I need to be be somewhat conscious of not taking in too much gas when I inhale. I remind myself of that on the boat before I splash (it's all boat dives here) and again at the surface just before I descend. And even still, sometimes I find myself feeling that "significantly up when I inhale / back down when I exhale" sensation that you described earlier, and it tells me (at least I think it tells me) that I'm taking in too much gas in my inhale. When I consciously tamp that back down, that sensation goes away, and my body doesn't feel like it's "starving for air". It can happen frequently during a dive because I still don't have nearly enough dives yet to have the "muscle memory" to instinctively know how much gas to inhale, so it requires a bit of thought - from time to time, without obsessing over it because that invariably kicks my SAC rate up again.
- Do you have an AI computer? I don't, but one of the advantages I could see to owning one is that it tracks your gas consumption throughout the dive, and being able to review that afterward might show you useful information - like generally your SAC rate is fine but there are moments in the dive where it spiked, which you can then maybe relate to something that occured during the dive (could be positive or negative) that caused the spike. Of course, my understanding is that DMs don't get paid a whole lot for their services so if you don't have an AI computer that might be too much of an investment at the moment, but it might give you a place to look.
Just a few thoughts from one less experienced than you...
Learning to breathe underwater really isn't easy, is it?
You have more in-water experience than I do, and much more training, so I don't want to say too much. But, a few things come to mind from my own learning experience with breathing from a cylinder...
- How long have you been a professional? If your total dive count is ~250 I'm thinking it's still early in your career. DMs where I am are usually doing at least a couple of tanks every day, at least 5 (sometimes more) days per week (unless it's low season). So depending on how you define "winter" (where I grew up in northern Canada it is arguably six months out of the year, and friends living in Finland tell me it's a similar climate!) that adds up very quickly. I ask this because for me if I am under any stress at all my SAC rate is significantly higher, and it could be that if you are still new to being a divemaster you will find your SAC rate decrease as you gain experience and find it less stressful... If I were a DM right now my gas consumption would be through the roof!
- It probably isn't what dive professionals want to do on their days off, but when you are working in SE Asia do you have opportunity or inclination to do any "fun dives"? Like, where you aren't the one responsible for a group - maybe just a dive with a buddy in conditions similar to what you are diving as a pro. And not that you should spend those dives focusing on your SAC rate, because that will defeat the purpose. Just a dive purely for fun. In that case, what is your SAC rate? If you could measure that you would have a "baseline" for that environment that you could then use for comparison against your "working" SAC rate.
- Gas consumption is (logically enough) not just a matter of breathing rate but also breathing volume. For me I need to be be somewhat conscious of not taking in too much gas when I inhale. I remind myself of that on the boat before I splash (it's all boat dives here) and again at the surface just before I descend. And even still, sometimes I find myself feeling that "significantly up when I inhale / back down when I exhale" sensation that you described earlier, and it tells me (at least I think it tells me) that I'm taking in too much gas in my inhale. When I consciously tamp that back down, that sensation goes away, and my body doesn't feel like it's "starving for air". It can happen frequently during a dive because I still don't have nearly enough dives yet to have the "muscle memory" to instinctively know how much gas to inhale, so it requires a bit of thought - from time to time, without obsessing over it because that invariably kicks my SAC rate up again.
- Do you have an AI computer? I don't, but one of the advantages I could see to owning one is that it tracks your gas consumption throughout the dive, and being able to review that afterward might show you useful information - like generally your SAC rate is fine but there are moments in the dive where it spiked, which you can then maybe relate to something that occured during the dive (could be positive or negative) that caused the spike. Of course, my understanding is that DMs don't get paid a whole lot for their services so if you don't have an AI computer that might be too much of an investment at the moment, but it might give you a place to look.
Just a few thoughts from one less experienced than you...
Myself (95kg) and a buddy (110kg+) outbreathed a little Japanese DM, it happens. Did we want longer dives yes absolutely but you get what you get.
In your case I'd sling a 40. Heck I wouldn't DM without redundancy. Then you can run down to a real min gas of 30 bar.
In your case I'd sling a 40. Heck I wouldn't DM without redundancy. Then you can run down to a real min gas of 30 bar.
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Hi @Tycksel
You have really stuck with your quest to improve your gas consumption. Your gas consumption is not all that high. At 15-16 L/min it is about average and at 17-18 L/min it is a little above average as compared to a fairly large ScubaBoard poll
Buoyancy, trim, propulsion, thermal comfort, relaxation, breathing. You have told us the first 4 are all pretty good. That leaves you with the last two and they are related. Gas exchange is most efficient when your lungs are inflated. Try a slow inhale with a larger volume than a normal inhalation. This is followed by a short pause with an open glottis. Then make a slow exhalation followed by a nearly immediate inhalation. This differs from the box breathing as there is no pause after the exhalation. I probably have something like 4-6 breaths per minute.
A larger cylinder would be an easy way to get you more gas and relieve your anxiety regarding running short. You told us that AL100s were eliminated because the increased diameter did not fit in the tank racks of your boats. Would you be able to get steel 12 or 15s (or HP 100 or 120s)? Of course, this would require that your operator be able to fill them to service/working pressure.
Good luck
You have really stuck with your quest to improve your gas consumption. Your gas consumption is not all that high. At 15-16 L/min it is about average and at 17-18 L/min it is a little above average as compared to a fairly large ScubaBoard poll
Another 1000 views, now >73,000. 865 votes in the poll.
The median, mode, and weighted average remain 0.5-0.59 cu ft/min or 14.2-16.9 l/min.
If you have not voted in the poll, please consider doing so. If your average RMV has changed, please change your vote.
Best diving to everyone
The median, mode, and weighted average remain 0.5-0.59 cu ft/min or 14.2-16.9 l/min.
If you have not voted in the poll, please consider doing so. If your average RMV has changed, please change your vote.
Best diving to everyone
Buoyancy, trim, propulsion, thermal comfort, relaxation, breathing. You have told us the first 4 are all pretty good. That leaves you with the last two and they are related. Gas exchange is most efficient when your lungs are inflated. Try a slow inhale with a larger volume than a normal inhalation. This is followed by a short pause with an open glottis. Then make a slow exhalation followed by a nearly immediate inhalation. This differs from the box breathing as there is no pause after the exhalation. I probably have something like 4-6 breaths per minute.
A larger cylinder would be an easy way to get you more gas and relieve your anxiety regarding running short. You told us that AL100s were eliminated because the increased diameter did not fit in the tank racks of your boats. Would you be able to get steel 12 or 15s (or HP 100 or 120s)? Of course, this would require that your operator be able to fill them to service/working pressure.
Good luck
Could you still pass the PADI DM physical tests? If not you are not that fit. Also lifting weights is not going to help consumption and may actually hurt it.
On the gaz consumption, @rsingler commented this: Average Gas Consumption
My take-out: even if you don't suffer from after dive symptoms, not breathing enough may result in a degree of hypercapnia which put you at risk underwater should you do an effort. Before this thread, I already considered that aspect of diving as a stupid competitive aspect, now I consider it as dangerous.
Air consumption is like a lot of proxy. It can be a indicator of experience. But you have to consider the other aspects and making it a goal tend to reduce its meaningful meaningfulness. In our case artificial measures to act on the proxy don't just reduce the meaningfulness, they may also be dangerous.
My take-out: even if you don't suffer from after dive symptoms, not breathing enough may result in a degree of hypercapnia which put you at risk underwater should you do an effort. Before this thread, I already considered that aspect of diving as a stupid competitive aspect, now I consider it as dangerous.
Air consumption is like a lot of proxy. It can be a indicator of experience. But you have to consider the other aspects and making it a goal tend to reduce its meaningful meaningfulness. In our case artificial measures to act on the proxy don't just reduce the meaningfulness, they may also be dangerous.
CG43
Contributor
The diver has stretch receptors for the lungs or rib cage.
When the lungs are full, you exhale more or less.
Possible exceptions are pronounced panic, obstruction of the airways due to e.g. glottis doughnut or medical causes.
Hello Tycksel :
Ok you can't use bigger tank(s) .
Then you should try the following breathing exercises on land:
Lie flat on the floor and breathe slowly and deeply until you are really calm.
1.) Put your arms parallel to your body, exhale, hold your breath until it becomes clearly uncomfortable and stop the time.
2. Place the arms about 90° to the body so that the shoulders and arms are stretched and the chest is as wide open as possible. This favors the volume of air that you can breathe in without significant pressure in the chest , for example 75% of your maximum lung capacity.
Now breathe calmly again and measure your breath hold time . Don't be surprised at the result!
Practice this on land and in the water.
In the water you can also breathe in 100% if you dive to a depth of at least 2 m afterwards.
If you practice this for about 5 weeks, you will probably not feel the need to constantly breathe in or out underwater while scuba diving.
Maybe you're stressing looking after your clients? I only have 100 dives but I'm pretty decent on air. I used to count and everything but now I just don't even think about it unless I'm deeper than 30M. The last thing that adjusted my air consumption was the venturi on my reg, I set it to provide air as easy as possible (before I thought that making it tighter would be better but no).
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I have referred back to @rsingler post many times
Over my last 1965 dives, my RMV has been 0.36 +/- 0.04 cu ft /min (mean +/- SD) this is 10.2 +/- 1.1 L/min. I do not have any signs or symptoms of CO2 retention.
Over my last 1965 dives, my RMV has been 0.36 +/- 0.04 cu ft /min (mean +/- SD) this is 10.2 +/- 1.1 L/min. I do not have any signs or symptoms of CO2 retention.
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