Air management question

[MXGratefulDiver]

Not if you dive solo. One of a number of reasons I think diving with a buddy is more dangerous than diving solo (as long as you are fully trained, fully skilled, and fully equipped).

Diving solo is more than just about training and equipment. I've met quite a number of people who just shouldn't do it ... they don't have the mental awareness needed to know how to keep themselves out of trouble ... nor an attitude sufficient to understand why that matters ...

... Bob (Grateful Diver)

 

[Kharon]

Diving solo is more than just about training and equipment. I've met quite a number of people who just shouldn't do it ... they don't have the mental awareness needed to know how to keep themselves out of trouble ... nor an attitude sufficient to understand why that matters ...

... Bob (Grateful Diver)

Yep - I said fully trained, equipped, and fully skilled. Mental awareness and the proper attitude are necessary skills. I agree, it's not for everyone. Personally, I love it.

 

[RJP]

To extend the time that 700 psi will last, as well as the rest of your tank, work on inhaling slowly over the span of 5 seconds then slowly exhale over the span of 10 seconds. You might not be able to do this at first but a 3 second inhale and 5 second exhale is still MUCH better than uncounted breathing.

Oxygen use by the human body is a "demand" function. You're advocating a "supply" solution. It don't work that way. Sort of like trying to improve gas mileage in your car by putting less gas in the tank.

Just as with your car, the only real way to make that 700psi last longer is to reduce your body's "demand" for oxygen.

 

[GrumpyOldGuy]

Oxygen use by the human body is a "demand" function. You're advocating a "supply" solution. It don't work that way. Sort of like trying to improve gas mileage in your car by putting less gas in the tank.

Just as with your car, the only real way to make that 700psi last longer is to reduce your body's "demand" for oxygen.

Mentally working to slow down your breathing rate can reduce the demand for oxygen (or dumping C02) if the high rate is due to being nervous rather than pure exertion. The old count to 3 or whatever number while you inhale / exhale works in this case, its a mental game more than physiology for nervous divers.

 

[Hatul]

Mentally working to slow down your breathing rate can reduce the demand for oxygen (or dumping C02) if the high rate is due to being nervous rather than pure exertion. The old count to 3 or whatever number while you inhale / exhale works in this case, its a mental game more than physiology for nervous divers.

I agree. When diving it's easy to get excited or anxious and hyperventilate or breathe shallow and rapidly. Shallow rapid breathing is inefficient because it ventilates the dead space rather than the alveoli. It's good to think slow deep breathing.

The simple rule mentioned above to keep 10* (depth in ft) + (300 to 500) in psi is a good approximation of Rock Bottom. Good enough for recreational dives.

If you have an AI computer you're also one step ahead as the Remaining Bottom Time (Galileo and others) does gas management for you on the fly. In solo diving just keep the RBT above 0 minutes, and in buddy diving keep RBT> depth(ft)/ 30 + 1 minutes with a generous tank reserve (550 psi) to maintain Rock Bottom.