Air Hog

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razorbackdiver

Contributor
Messages
126
Reaction score
53
Location
Little Rock, AR
# of dives
200 - 499
My experience level is 14 fresh water dives and 7 saltwater dives (deepest of which was 120Ft). Though limited experience I feel extremely comfortable under water. I am 5'11'', 225 LBS, out of shape, and a chain smoker. I dive a steel 120. Problem is people of similar size but more experience are using AL80 still have 12 to 15 hundred pounds left, while have to go below 500 pounds on the same dive profile. Is this a purely physical problem to be solved by heathier lifestyle or are there drills or something I can use to reduce my air consumption?
 
It easily comes down to 4 things. In my book.
1) Lifestyle. Smoking does a lot of damage to your lungs and makes your body inefficient at working with oxygen and being out of shape does not help your body use oxygen more efficiently. Both together are going to shoot your air consumption through the roof.
2) Buoyancy control pretty simple newer dives (and I'm still one) filled with their BCD/drysuit alot trying to get the right amount of air in for neutral buoyancy and over weighting.
3) Breathing cycle Having a nice fluid breathing cycle help cut down on air consumption. You speed it up as needed but night slow breaths in and out help keep your body from just wasting air as your alveoli can only process so much at any given time.
4)Racing.Simply put some people push themselves past the point of what their body is able to do and it it forces the body into Aerobic respiration. If your buddy is swimming like a torpedo tell them to slow down. The pace should be set by the slowest member not the fastest.
The first one is pretty much straight forward if you improve your lifestyle by A) quitting smoking and B) getting in shape your body will A) love you for it and slowly recover to a certain extent and allow your lungs to use they air you break more effectively and B) getting in shape will help lower your bodies needs for air by making it more used to doing work and not going into full blown aerobic respiration(which shoot your air consumption through the roof). This also lets you get into using an effective breathing cycle without over stressing your body and building up CO2. Being in shape pushes this

The second point is just a skill that takes time, practice and a little bit of side homework to make sure your not over weighted. Do a quick buoyancy check when you get in and when you get out of a dive. less weight means less mass less mass means less you have to push through the water all boils down to less air used. Buoyancy also come into play as if your adding too much air to your BCD because your over weighted you have to let that air out when you come back up thus wasting air. This also effects your time. The further off you are from the horizontal when your diving the more wasted energy from each kick cycle. Thus energy=air and you waste air in a sense doing that.

But I'll be blunt here as well I think the first paragraph sums up your biggest issue at this point without seeing you in the water. While you do not need to be in the best shape to dive but to really enjoy it and dive. you should be trying to get in better shape than you are (lifestyle as well) so you can enjoy diving more and stay down longer ( within reason of course).

Also Air consumption decreases with time as you get used to the underwater world and its many challenges.
 
There is one drill immensely effective for redusing the air consumption..
Dive, Dive, Dive and then Dive some more! :)
Your consumption will go down with experience. There is some people advocating certain breathing techniques, but they have issues of their own, which is why I wont recommend them.
It is not PURELY a physical problem but if you feel like youre out of shape (which the weight COULD suggest, you dont mention if youre more muscular or have a heavier bone structure than average), exercosing a little could help as well.
Beinge in good shape wont hurt your general health either.
 
I'm 5' 11" and currently weigh in at 245 lbs. I just had a knee replacement in December and as a result have not been as active as I'd like. I also went to Fiji for a couple of weeks at the end of March. I'm 60 and will never again be the football player/wrestler of my college days. In Fiji my sac rate averaged .45. An al 80 lasts an hour quite comfortably on most dives. The difference? DIVING!!! When I'm not recovering from surgery my normal routine is 3 times a week mountain biking and a couple of 2 mile walks a week along with pushups and situps 3 times a week but I have been an absolute slob since the surgery (except for physical therapy, about which I was pretty anal). My point is that diving is not an aerobic exercise (unless you are either an idiot, inexperienced or in very unusual conditions). Being in shape is highly recommended but not necessary for most diving. Of course your health is another matter but I'm not going there. That was not the question by the original poster as I understood it. On my second dive trip I fell in with a bunch of kindly Texas reprobates who helped me with my trim and weighting. That help combined with 25 dives in 6 days resulted in my air efficiency improving by 50%! Wow. So Diving is the single best solution to your problem - and it's FUN. Dive a lot, ask for tips from more experienced divers and then dive some more. Have a blast. Maybe at some point hire an instructor to help you with trim, weighting and help you be a "zen diver" (only moving what needs to be moved, when it needs to be moved, and how to move "it" most efficiently).
 
Although fitness doesn't hurt, especially in currents or anywhere where you are having to WORK to dive, it's not really the thing that will make the biggest change in your air consumption. That thing is efficiency.

One of the biggest problems that relatively new divers have is instability. This comes from several sources:

1. It takes time to learn to balance that big, negative keel on your back. This is more noticeable with steel tanks, and especially with big ones, because at the beginning of the dive, they are quite negative. Get the least bit off to one side, and that tank just wants to keep going. Especially if the new diver is using a BC that doesn't fit real well, it's very easy for the tank to get out of the middle of the diver's back and begin to cause issues. This rotational instability results in a lot of hand-waving.

2. Buoyancy control is not mastered in a day, or a handful of dives. New divers tend to be adjusting their BCs a lot, especially if they are diving in cold water with big steel tanks. Big steels are, as I already said, quite negative at the beginning of the dive, which means you have a fair amount of air in your BC or dry suit to compensate for that gas, and that's a big air bubble to manage, especially on shallow dives. In addition, the gut-level reflex to vent or add air to something isn't solid yet, so new divers often react to buoyancy problems with a lot of hand movement, before they remember to adjust their buoyancy. Either that, or they end up swimming down against a buoyant BC or suit, which is hard work.

3. If you are diving gear that is new to you all the time, you haven't had the chance to figure out how to distribute your weight to make you horizontally stable, so you may have a pitch problem. What this means is that you can't STOP, because if you do, you will tilt feet or head down. This means you have to swim all the time, and that uses up air faster.

4. Quite frequently, especially in cold water, the large amount of weight that is required is massed too low on the diver's body. When you combine that with the fact that many new divers just don't want to flatten out, but like to keep their hip joints flexed, you have a strong tendency to dive head up/feet low. If you think about it, that has two issues that come with it: One, you are presenting a large surface area to the water, when you are trying to move forward, compared with the small profile you have if you are perfectly horizontal. Two, and more pernicious, is that if you kick, you are simultaneously driving yourself forward and UPWARD. To avoid rising in the water column, you have to keep yourself negative. This means that some portion of the work you are doing underwater is being done to create no net displacement at all, and that's just wasted muscle activity and wasted gas.

5. In order to fight all those destabilizing forces, new divers frequently want to swim fast, because strong forward motion, just like with a bicycle, tends to produce less wobbling. (The flip side of this is the new diver whose kicking technique is so inefficient that he doesn't go anywhere, despite a ton of leg activity.)

6. Instability is an insecure feeling, and this is the source of a lot of the anxiety or discomfort that new divers feel underwater. Anxiety produces an inefficient breathing pattern, consisting of rapid, shallow breaths. Since the only air that helps get rid of CO2, or deliver oxygen to the blood, is the air that gets down into the small air sacs in the lung, the air that ventilates the trachea and major bronchi does you very little good -- and when you take rapid, shallow breaths, most of the air is just exchanged in the big airways. Learning to relax and take longer, slower breaths improves gas exchange, and means you move less total volume through your lungs in any given period of time. But telling people to dive a lot and relax is really not productive, unless you help them understand WHY they are not relaxed, and what they can do about it.
 
I was told that your air consumption is not something that you can reduce DRASTICALLY. However, that said, the more often you dive, the better shape you're in, and the more comfortable you feel under water, the lower your air consumption is going to be.

I'd also pay attention to fin kicks - using the frog kick uses up far less air than using the regular fin kicks.
 
Razorbackdiver,

You should have plenty of improvement to look forward to. However to some extent you are what you are too.

Frequent diving will build comfort and skill. Diving with a spirit of continuous improvement will build good skills, the goal, being that you are a calm seemingly effortless diver in the water.

With some more dives under your belt that 120 CF cylinder should soon level the playing field with 50% more air than buddies using 80CF cylinders.

Personal physiology and the effects of prior smoking will certainly enter into things but if you do everything else right those can often become minor factors. There are some diver who are simply power breathers even with skill, relaxation and fitness. With 21 dives you aren't even close to resigning yourself to being such a person. If that proves to be the case doubles or limiting your dive plan are the obvious options.

Knowing your present consumption your dives should be planned such that you get back with a suitable reserve. Your prime objective is not to maximize your buddies bottom time. Everyone needs to consistently return safely.

Pete
 
Pretty much the reason why I quit smoking. I am not in bad shape at all, but everyone was killing me on air consumption. I was embarassed into quitting
 
Don't worry too much about your air consumption, you are still a novice diver. Give it some more time.

Being out of shape will really increase your air consumption, especially during repetititve dives over multiple days. As you get more and more tired, it will become very difficult to keep your air consumption under control.
 
Many good points are made above. Buoyancy control and not "running around" under water are the two biggest ways to reduce consumption in my book. Let's remember, too, that there a physiological differences between individuals. Some very much in shape athletes go through air because they have very large lung capacity. No doubt the op is breathing more rapidly that a person who had good lung efficiency and a more streamlined profile would. It's always a good idea to not smoke, and always a good idea to keep a reasonable body fat level. Being an active diver is a good incentive and a good reward for doing both.
DivemasterDennis
 

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