Air consumption tips?

[Beerkowski]

Okay, first of all, total n00b, first post, so please be kind.

I'll save the geekout about being hooked on diving and how I am completely blissed out and why for another post.

I tried to search and didn't find a thread specifically devoted to air conservation. I can't believe there isn't a sticky on it!

I am an air hog. I only have 8 dives (all in Cozumel) under my belt since getting my card.

My first dive was only 32 minutes, i didn't have enough weight so I couldn't do a safety stop and I hit the surface with maybe 150 lbs of air. I gave myself a VERY stern talking to about all the safety protocols I learned but didn't follow and everything I did wrong on the dive and then decided to focus on being a SAFE diver, not just an excited one.

For the rest of the week I tried to really focus on my buoyancy and air consumption (while my facial muscles ached and my mask leaked from my HUGE grin). I'm a big guy (5'11" and 250 pounds) so I'm working on the weight problem as a way to use less air, but here's the other things I have been focusing on:

• Conservation of movement (buoyancy helps alot here, I know)
• trying to breathe more shallowly?
• Hydrodynamics -swimming in a horizontal position without dangling, dragging equipment
• THINKING better -relaxing, thinking ahead, relaxing, reading the reef and the water conditions so I don't have to exert as much physical effort and also trying to relax

A lot of these get better with sheer practice, I'm sure.

I spent 34 of my first 41 years on earth as an enthusiastic snorkeler. I played trumpet and was in choirs in high school (all those years ago) I was VERY proud of having a big lung capacity and being able to hold my breath for minutes at a time, so deep breaths were what I took when I got near water. It seems like having big lungs is a BAD thing in SCUBA. I'm working on my breathing technique, but I really don't know what I should try to do... take fewer breaths? take more shallow breaths? try to exhale as long as possible... I have tried all of these and nothing really seems to be THE answer. By my last dive, I was following all my internal safety rules and I was up to 50 minutes (although it was a pretty shallow dive).

WOW I am really rambling here, sorry.

I'm off to Maui in two weeks for round two of dive obsession, and I really want to have a plan. Any advise here would really be appreciated.

 

[drrich2]

I'm 6'1", close to 275#, and on a typical warm water tropical dive in Bonaire, for example, an AL80 might last me 40 minutes or so. So yes, big guy, big lungs, you're not going to match lean, petite women, for example.

trying to breathe more shallowly?

I don't think that's the answer. The respiratory dead space (air in non-gas exchange areas like windpipe, bronchi, etc...) is the same, but you're reducing the air volume reaching the gas exchange portion of the lungs. Be mindful that the need to excrete CO2, rather than to take in oxygen, is the main thing driving your respiration. If you skip breath (significant pauses between breaths), you can retain CO2 & get severe head aches (happened to me once). Someone posted in another thread about breathing a little bit deeper than usual for land, if that helps any.

For whatever reason, I find it hard to 'sip' air on inhalation; I guess because the air's coming in under a bit of pressure. I have more success exhaling slowly, in fact sometimes in 'pulses' (instead of one continuous burst).

Otherwise, calm yourself as tranquil as you can, go slow to reduce CO2 production & water drag, stream-line if you can, don't over-weight yourself & stay horizontal in the water column as best you reasonably can.

And when you can, use bigger tanks. The aluminum 80 is a middle-of-the-road tank, bearable for petite people that offers enough air to give most larger folks at least some bottom time, but one size does NOT fit all. Remember what you learned about pipes; a small increase in cross sectional diameter causes a large increase in surface area? Well, bigger lungs have a lot more volume to fill (and the diver probably a lot more cross sectional mass to push through the water's resistance).

In Cozumel, Living Underwater is a dive op. with 120 cf steel tanks. Love those whoppers!. Got a roughly 1 1/4 hour dive in with one. Wonderful.

Richard.

 

[Ste Wart]

My advice would be; don't think about your breathing. Otherwise you'll end up worrying about it.

32 minutes is brief, but not unheard of. Once you've dived a bit more, you'll find you become more comfortable with the underwater environment and your air consumption will drop.

 

[joel smith]

The best thing you can do now is DIVE , DIVE , DIVE , I had the same problem it will get better. Watch other experienced divers, mimick them.

 

[Splitlip]

Don't breath shallow! On the contrary, take a deep breath, pause (dont hold your breath and don't think of the "K" sound. Think of the "H" sound. ) exhale completely then repeat as needed.

 

[joel smith]

The group I dive with use Worthington Steel 100 tanks this also gives more air , plus helps with buoyancy issues.

 

[j yaeger]

...remain calm...and carry on!... as the brit saying goes
keeping relaxed is #1
dont overthink it!!!
have fun
yaeg

 

[herbdb]

I am also a big guy, my first trip to the Keys several years ago, I could only get 25-30 minutes out of an Al80 on a shallow dive. Last summer, I could get double that. The difference is just practice, buoyany control and getting more comfortable.

Get out and dive.

 

[TSandM]

I enjoyed your post, and I can just imagine the grin.

You really have thought it through well. The biggest improvements in air consumption for new divers come with increasing efficiency. Being efficient means maintaining neutral buoyancy without a lot of BC adjustments (which means proper weighting, too). It means streamlining your equipment as best you can, and reducing movement, including the very inefficient use of the hands. Reducing speed, avoiding exertion like swimming against current, and in Coz, reading the reef for places where you can shelter and stop for a bit, are all part of being efficient.

One thing you may not have thought about is trim. If you are horizontal, any force you generate with your kick is driving you forward (or backward, depending on the kick). But if you are at an angle from the horizontal, two things happen. One is that you are presenting a much larger surface area to forward movement, which increases the resistance and therefore the effort required to move in that direction. The other is that your kick is no longer directed forward -- some component of it (increasing with the degree of head-up trim) is driving you UPWARD. To counter that, new divers have to remain slightly negative, so that they do not move steadily shallower. In other words, you're kicking yourself upwards and having to sink to avoid rising; all of that is wasted exertion. Being horizontal and neutral reduces the effort, and also allows you to stop whenever you want, without having to swim circles around the object you want to view.

One great test for this is simply to stop kicking and glide for a moment. If you start to sink, you know you were not neutral when you started the exercise. (Frog kick is a great kick for this, because there is a glide phase built into each kick cycle, and that glide phase is a constant buoyancy check.)

The very last thing you should think about is your breathing. It IS true that the most efficient breathing pattern on scuba is different from what you probably use when sitting at your computer. On land, we do not have to worry about making efficient use of the gas supply we have. In the water, we definitely do. With each breath we take, we move air through structures that participate in gas exchange (the air sacs in the lungs, or alveoli) and through structures which are simply conduits (the trachea and bronchi). We MUST move a certain amount of air through the alveoli, to maintain a normal carbon dioxide level in the blood, which is very important to the body (and the brain). Clearly, many small breaths will result in ventilating the bronchi (dead space) multiple times, and fewer, larger breaths will result in the same amount of air through the alveoli, with fewer exchanges through the dead space. So slower is better, right?

Not quite. The problem with slow, very deep breaths is that, particularly for big guys, the lungs are a very large air space affecting buoyancy. Taking a slow, very deep breath is like filling your BC up, and you will rise in the water column. If you then exhale strongly, you will fall. Those excursions CAN be big enough to begin the process of expanding the air in your BC, so that, if you inhale deeply, when you exhale, you may not stop rising -- then you have to adjust your BC and start the cycle over again.

There is a rhythm that allows you to take a deeper-than-normal breath, and release it just as you begin to move upward, and then begin to inhale again just as you begin to move downward. This is the rhythm that the "fin pivot" exercise in OW class (if you did it) is designed to help you find. It's a breathing pattern that is more like meditation or yoga than normal land breathing, but it is not composed of huge breaths. I think that, more than anything else, this particular thing takes time to master -- and even more time to learn to maintain, even in the face of distractions or anxiety. But breathing is the key to neutral buoyancy, and neutral buoyancy is the key to efficiency, as well as being one of the most delightful and seductive things about diving.

Hope this was helpful! (It was certainly LONG )

 

[freewillie]

All of the above.

Watch your trim, danglies, etc. Use clips etc. keep guages and consoles close to the body.

Dive as often as possible to work on buoyancy.

Swim slowly. The faster you swim the more air you will consume. For the same AL 80 you will get more minutes cruising leisurely along the reef than racing along like a torpedo. Besides, you will see more by swimming slow.

Don't forget the most effective way to increase your air consumption is to increase your physical fitness. Check out archived articles dive magazines for specific tips. Bottom line, the better physical condition you are in the better your air consumption will be even after correcting for weight, trim, etc.

Good luck!! Have fun and dive safe.