Should all divers have a redundant air source on every dive?

[Scuba-Stu]

Actually, this really isn't true. What limits breath-holding for almost all of us is CO2 production. Whether you begin breath-holding with your lungs full or empty doesn't matter very much, because you aren't going to run low on oxygen before the buildup of CO2 overcomes your conscious inhibition of respiration. (The reason I say "almost all of us" is that freedivers learn to stifle the urge to breathe long enough to get hypoxic.)

While I agree 'what limits breath-holding for almost all of us is CO2 production' I disagree that it doesn't matter whether or not you have gas in your lungs especially while your trying to swim.

 

[Walter]

Wow...you "seasoned" divers are all starting to sound like my parents when they told us about how they got to school! "Up hill in three feet of snow carrying all our books...BOTH WAYS!"

You missed the point. The underwater swim is still in the standards as part of the swim test for some agencies. If you can do it without fins, it should be so much easier with fins.

wouldn't it be worse with ONE fin?

Nope. Swimming with one fin (flutter or dolphin) is much easier than swimming with boots, but no fins.

 

[String]

Boots with no fins is worth everyone trying in the confines of a pool just to see how completely useless you feel.

Your legs will drop, feet will go at 100mph and you'll go absolutely nowhere at all.

 

[MXGratefulDiver]

While I agree 'what limits breath-holding for almost all of us is CO2 production' I disagree that it doesn't matter whether or not you have gas in your lungs especially while your trying to swim.

What matters most is keeping your cool, and doing what you need to do in as relaxed a manner as possible. This will keep CO2 production to a minimum.

One of the most difficult tests we took in DM training (and what seemed at a literal level to be one of the most useless) was skin ditch and recovery ... freediving to the bottom of the pool, removing your mask-fins-snorkel, surfacing, then diving back down and putting them on and surfacing with a cleared mask & snorkel.

Seemed really hard until you learned not to rush, not to push, just to relax and take all the time you needed to do it ... then it seemed pretty easy.

Lynne's right ... it's not about how much O2 is in your body ... it's about how much CO2 is. You can go a long time without breathing if you relax ... and not much time at all if you don't.

... Bob (Grateful Diver)

 

[Thalassamania]

While I agree with Bob, I need to ask, "Why would your buddy not be within 2 to 3 kicks?" Mine is.

 

[Scuba-Stu]

What matters most is keeping your cool, and doing what you need to do in as relaxed a manner as possible. This will keep CO2 production to a minimum.

One of the most difficult tests we took in DM training (and what seemed at a literal level to be one of the most useless) was skin ditch and recovery ... freediving to the bottom of the pool, removing your mask-fins-snorkel, surfacing, then diving back down and putting them on and surfacing with a cleared mask & snorkel.

Seemed really hard until you learned not to rush, not to push, just to relax and take all the time you needed to do it ... then it seemed pretty easy.

Lynne's right ... it's not about how much O2 is in your body ... it's about how much CO2 is. You can go a long time without breathing if you relax ... and not much time at all if you don't.

... Bob (Grateful Diver)

Thanks Bob. I wasn't disagreeing just trying to state that are reasons that you inhale and hold your breath when free diving or swimming vs expelling all the air before you dive. It both it provides you with o2 and allows your body the opportunity to expel more CO2.

 

[boulderjohn]

If you want to count bolt 'n' pray as an option then fair enough but again i dont class that as a useful option for anything deeper than 10-15ft in my case.

For my own planning i dont class bolt 'n' pray at all as a safe option so i dont personally accept that as an option for me.

You've been repeating all of this "bolt and pray" stuff for years, in many threads. I don't know why it is, though, that I have never noticed you participating in the various threads that have focused on people telling their experiences with CESA, threads in which everyone pretty much talks about how easy it is. In one thread, in fact, I even commented on your lack of participation, wondering if you were on vacation or something.

To summarize, a whole host of Scuba Board participants have talked about their "no big deal" experiences with a CESA, from depths surpassing even 100 feet.

I myself know a number of people personally who have done CESA's from depths greater than 75 feet, with no problems.

Several years ago, when you were praising BSAC for doing away with CESA, I contacted the director personally by email and asked what would happen to one of their divers if the unthinkable happened and they were indeed out of air without a redundant air supply. He said that diver would do a CESA. Why not teach it then? The answer: What's to teach? You exhale and ascend.

I am by no means advocating that we count on this as a routine part of our dive plan, but I don't understand the source of your "bolt and pray" phobia about it. If I am ever in that situation (which I doubt), I won't bolt, because I am trained better than that, and I will not see any need for prayer, since I am confident of the outcome.

If you don't feel you can personally do it from depths greater than 15 feet, then perhaps I can get you in touch with some one who can work on your technique a little. If you are in my area some time, I can give it a whirl myself.

 

[udtfire]

if in your mind you ask the question then you must seek the answer. as i tell my students the only problem you cant solve underwater is no gas. and we teach two is one and one is none. so by that rule one gas source is no source. but you the diver must make the choice there is no rite or wrong just safe diving be safe hope to see you in the water

 

[captain]

if in your mind you ask the question then you must seek the answer. as i tell my students the only problem you cant solve underwater is no gas. and we teach two is one and one is none. so by that rule one gas source is no source. but you the diver must make the choice there is no rite or wrong just safe diving be safe hope to see you in the water

So are you saying there is no gas at the surface, that is my second and last time I checked there was more than enough. I guess I better check again.

 

[LeadTurn_SD]

if in your mind you ask the question then you must seek the answer. as i tell my students the only problem you cant solve underwater is no gas. and we teach two is one and one is none. so by that rule one gas source is no source. but you the diver must make the choice there is no rite or wrong just safe diving be safe hope to see you in the water

I think I understand what you are trying to say, but from first half of your statement you are saying there is a right and wrong answer.

The original question that started this thread is: "Should all divers have a redundant air source on every dive?"

The key point here is "on every dive". Some people strongly believe the answer is "yes", while I and some others believe no. Not for "every" dive.

For many dives and many divers, the "atmosphere" is probably enough redundancy.

Best wishes.