Controlling and reducing air consumption

[Steelyeyes]

Trim and weighting are important.

Going slow is the most impactful in a couple of ways. Increasing drag is not a linear function. For a fully submerged object that's relatively cylindrical it takes 8 times the force to double the speed. The difference is to compensate for drag and turbulence caused by the increased speed of motion through the water. Less speed mean less force, less force mean less metabolic expense to produce that force which translates to lower CO2 production. The result is a lot more efficient use of your breathing gas.

The lower your metabolic rate the more insulation you need to stay warm. Staying warm helps cut gas use too.

The end result is that not only do you get more bottom time you see a lot more stuff. That's a lot more bang for your buck.

 

[tdallen]

The lower your metabolic rate the more insulation you need to stay warm. Staying warm helps cut gas use too.

Yes, that's something I'm noticing as a new diver. As I get more comfortable and stop thrashing around so much, I'm getting cold! Time for a full 3mm suit in situations where I used to be Ok in a shorty.

 

[The Chairman]

Apologies, but as a new diver, I'm not sure what sculling is.

Mea culpa... sculling, or more accurately, sculling with your hands, is also called "fly swatting" and is the act of trying to correct trim, buoyancy or swim with your hands. It's OK if you don't have the use of your legs, but other than that, all it does is to generate excess CO2 and mask trim and buoyancy issues. Learn to clasp your hands together in front of you. You can leverage that to assist you with your trim and it will stop you from swatting flys.

FWIW, I have edited that first post of mine to say "sculling with your hands".

 

[uncfnp]

What sort of diving requires less energy than walking? Do you use a DPV?

Drift diving Cozumel!

 

[uncfnp]

It's tough with the broken English but you make some valid points. Not so sure about the smoking though.

caruso. Gas consumption is a function of volume. The volume in the tank verses the rate and volume of each breath. The heavier you breathe, the faster you use gas. And it would seem logical to some that smokers as you say

Smoking damages the lungs without question and reduces the effectiveness as to how breathing gas is exchanged and absorbed into the vascular system. Anyone who maintains that the lungs of a smoker are more efficient at gas exchange is in the same camp as those who say recreational drugs are good for brain cells because they only kill off the weak ones.

but although I have never seen any research on gas consumption in smokers specific to diving it is a fact that, because smoking can damage the lungs, a smokers usuable lung volume can go down. And as @АлександрД stated eventually their sensitivity to CO2 can decrease. So yes, I could see prehaps why they might use less gas.

Disclaimer. This is not an endorsement for smoking!

 

[Youngandfree]

As a new diver that has only done a 4 post cert shore dives,being in better cardiovascular shape has to help. Where I was at, we had to gear up and walkout from our ocean front hotel, to the waters edge, and then swim out almost 100 yards to our dive spot. I was quite out of shape and 30lbs heavier. I was sucking wind so bad I couldn't catch my breath before ever putting my regululator in to go down. And it probably took 10 minutes under to catch my breath, aside from my dive buddies out swimming me and me working hard to stay up with them. My trim and buoyancy was definitely off, so I fought that stuff as well. I'm going back to FL in July, and we are diving off my BIL'S boat, instead of shore diving, so I'm hoping that I will be fresh going in and should have a better time with my air. Btw, I sucked an aluminum 80 down in about 45min. I'm down 30lbs, and working on swimming laps in my gym's pool using fins and no arms to improve my technique and lung capacity before then.

FWIW, my instructor and BIL that helped me both said my first 4 dives, including a shore night lobster dive, are harder than most newbies get, and they didn't baby me any. I plan on being in better shape to be able to enjoy it more this summer, vs just being one of the hardest physical challenges I've had.

 

[caruso]

smoking can damage the lungs, a smokers lung volume can go down. And as @АлександрД stated eventually their sensitivity to CO2 can decrease. So yes, I could see prehaps why they might use less gas.

Disclaimer. This is not an endorsement for smoking!

Smoking causes lung tissue damage and scarring which would naturally reduce the effectiveness of air exchange which equates to wasted gas and the need to breathe more frequently so you've got a smoker with smaller usable lung area and less effective gas exchange which can lead to more frequent inefficient shallow breaths compared to a nonsmoking diver with larger and more effective lung capacity who can take deeper, slower, less frequent breaths.

Drift diving Cozumel!

It's been my experience that drift diving can require an intensive amount of physical exercise for a boatload of reasons- working to stay on a patch of reef by turning 180 degrees to the current, maintaining trim and buoyancy in the stiff current, maintaining a safety stop without a line to hold onto, and swimming back to the boat is sometimes necessary even in a "live boat" situation. Lots of times the current abates and you've got your typical dive which can involve a lot of finning to see interesting areas of reef. Plus the climb up the boat ladder and the work involved getting the fins off while you're holding on can be rather strenuous. At any rate, it's surely more of a workout than a walk around the block

 

[scrane]

It's been my experience that drift diving can require an intensive amount of physical exercise for a boatload of reasons- working to stay on a patch of reef by turning 180 degrees to the current, maintaining trim and buoyancy in the stiff current, maintaining a safety stop without a line to hold onto, and swimming back to the boat is sometimes necessary even in a "live boat" situation. Lots of times the current abates and you've got your typical dive which can involve a lot of finning to see interesting areas of reef. Plus the climb up the boat ladder and the work involved getting the fins off while you're holding on can be rather strenuous. At any rate, it's surely more of a workout than a walk around the block

I must be in better shape than I thought. I can drift dive all morning and not break a sweat.

 

[caruso]

I must be in better shape than I thought. I can drift dive all morning and not break a sweat.

Me too! But I get a bit fatigued after 2 morning and 2 afternoon dives. Sleep comes easy...

 

[divad]

FWIW, I have edited that first post of mine to say "sculling with your hands".

Also known as "crazed-maniac-technique."