Sharing air to extend bottom time

[Scorow]

On my DSD a couple of years ago, the instructor/DM shared air with one of the two other DSD divers in our group (three of us total), solely to extend his (and thus, our) bottom time (the diver having gone through his air quickly on the first dive). I didn't appreciate at the time how ridiculous that was on many levels, not the least of which was trusting an untrained diver to switch regs and clear at 40 feet. Everything went fine. It seemed iffy to me even then, but knowing what I know now, it is difficult to believe that was done.

 

[redacted]

I didn't appreciate at the time how ridiculous that was on many levels, not the least of which was trusting an untrained diver to switch regs and clear at 40 feet. Everything went fine. It seemed iffy to me even then, but knowing what I know now, it is difficult to believe that was done.

While I do agree with the concern of the dive guide or DM becoming too focused on one diver if he shares his air to do his job well, the issue o switching regs is (should be) simple BS. It is a basic skill required to complete OW. If you put it right up there with parallel parking during driver training, then get out and practice this skill skill until you are comfortable. Otherwise, do others a favor and ebay your dive gear and head for the driving range where you may not be such a danger.

 

[JamesK]

While I do agree with the concern of the dive guide or DM becoming too focused on one diver if he shares his air to do his job well, the issue o switching regs is (should be) simple BS. It is a basic skill required to complete OW. If you put it right up there with parallel parking during driver training, then get out and practice this skill skill until you are comfortable. Otherwise, do others a favor and ebay your dive gear and head for the driving range where you may not be such a danger.

While normally I would agree with you, and do on this post, I feel you are out of context slightly. Scorow was talking about folks on a Discover Suba Diver class, not OW "graduates".

 

[redacted]

I did not realize what DSD was. That does make a difference depending on the prep training they receive..

 

[Peter Guy]

Sea Cobra (described as a NAUI Course Director) wrote

Sharing air should never be used to extend someone's bottom time so they can look at pretty fish a little longer.

Just a bad plan.

OK, why the hell is is "Just a bad plan?"

Long before I became a "PADI Professional" I was quite comfortable swimming around breathing off one of my buddy's 2nd stages which was connected to her first stage by 7 feet of hose. What's wrong with doing that? She could swim and look at the pretty fishies, I could swim and look at the pretty fishies -- we just mosied along various reefs breathing off the same tank. Pray tell, why is that a "bad plan?" What, for Pete's sake, is "bad" about it?

Let's just look at the number of things that could go wrong -- a. I screw up and the reg comes out of my mouth -- oops, I just put my reg back into my mouth and continue swimming. I don't know about you, but I was taught I could survive having the reg come out of my mouth by accident -- that, in fact, I could actually survive for as much as 30, maybe even 40 or 60 seconds without having to have a reg in my mouth. OK, that's one bad thing with no negative consequences.

As to "b." -- I can't think of any "b." -- what else could go wrong?

Sea Cobra -- the problem I have with Black/White people like yourself is that you don't seem to be able to think outside of any box -- you know what you know and if it isn't part of that, IT IS BAD. No, it is just different. Don't you WANT to have your students (not to mention your instructors) comfortable being able to share air, take pictures, blow bubble rings, whatever? I, for one, was taught that sharing air is NO BIG THING whether it is in 3 feet of water, 100 feet of water or 1000 feet back in a cave. It just is -- you put your lips around the regulator and you breathe. What's "bad" about that?

And yes -- I have shared air for kicks, I do share air for kicks and I will share air for kicks -- does this make me "bad?"

 

[RTee]

I have done it on some occasions locally with dive buddies I regularly dive with (one individual in particular who is not frugal when it comes to air consumption) but as a dive buddy and not DM. I recall one particular trip South when we were diving as a group of friends with one DM. When my air hog buddy reach 1200 PSI when most of us were still around 1800 - 1900 psi, we started a rotation, ie he would be towed by one diver for 200 - 300 psi or so and then moved to another one (just like a remora). When the DM turned around and saw us, he got greeted by 5 OK signs and we kept going. We all finished the dive with about 500 psi back on the boat. This was a drift dive and the alternative was for everybody to go back up at the 20 mins mark as it was a all or nothing type of dive.

The other example that comes to mind was during our last trip to Bonaire. Our group of 8 divers (mostly DMs and instructors) did a two tank boat dive on the wildside and an insta passenger showed up. He ended up being paired with the DM as we were already paired up. Two mins into the dive, I knew we were in trouble. We were doing a drift dive and this individual was behaving worse than a bee in a flower field...swimming left, right, and center. To keep this story short, the DMs ended up air sharing with the bee in order for the rest of us to have decent dives. How bad was he, bad enough for one DM having to revert to a top cover position and give us the lead on the first dive and almost putting buddy on a leash on the second dive. He knew several of us from previous visits not only from a cert perspective but also a diving perspective and knew we would have no problem taking care of ourselves.

 

[Mr Carcharodon]

T4e

Sorry misread details of your post. I think the air share was fine. But both of going to 200 psi is cutting very close unless the last part of the dive was very shallow.

Consider doing a search on "rock bottom" here.

 

[ferris213]

On our third dive after certification the DM encouraged my wife to continue her dive on his occy even though her tank was down to about 30bar (plan was to surface with 50) With no pre-planning, that late in the dive, with a very inexperienced diver, I realise now it was a terrible decision.

If it was with a regular buddy and planned for, and was done when the LOA diver still had plenty in their own tank, I don't have a problem with it.

 

[DevonDiver]

Let's just look at the number of things that could go wrong -- a. I screw up and the reg comes out of my mouth -- oops, I just put my reg back into my mouth and continue swimming. I don't know about you, but I was taught I could survive having the reg come out of my mouth by accident -- that, in fact, I could actually survive for as much as 30, maybe even 40 or 60 seconds without having to have a reg in my mouth. OK, that's one bad thing with no negative consequences.

Peter, whilst I agree with you that air-sharing is a relatively simple and low-risk procedure, the accident statistics do point towards this not be the case universally. What you, or I, or many/most members of Scubaboard (a specific community that defines itself by displaying an above-average skill set, education and interest in scuba diving) find easy, stress-free and uncomplicated - may not be seen in the same light by the 'general' diving community - the 'once-a-year'ers'.

Practice is practice. Using an emergency technique for convenience to extend bottom time for a low-on-air diver, in lieu of proper gas management is not practice.

In that respect, I would isolate the issue of being 'low-on-air' as my primary concern. Sharing air in that circumstance is acceptable - for ascent, but not for a continuation of the dive.

what else could go wrong?

From what I've read and, to a lesser degree, witness for myself; panic and buoyancy complications.

From the article: Common Causes of Open-Circuit Diving Fatalities

Emergency ascent (55%), insufficient gas (27%), and buoyancy trouble (13%) were the most common disabling agents and, together, accounted for 95% of the 332 deaths. Rapid ascent was witnessed or recorded by dive computer in over half the cases with emergency ascent, but emergency ascent also included divers who were assisted to the surface, made free ascents, or buddy breathed (Table 2). Panic was reported in about one-fifth of cases with emergency ascent, but the reason for the emergency ascent was unknown in about one third of the cases.

I, for one, was taught that sharing air is NO BIG THING whether it is in 3 feet of water, 100 feet of water or 1000 feet back in a cave. It just is -- you put your lips around the regulator and you breathe. What's "bad" about that?

1. The answer to that question is entirely dependent on the individual concerned. For you, me... and most readers of this thread.... nothing is "bad" about it. For someone else... it may be the most intimidating and scary thing they've done underwater.

2. In respect of specific issues and examples raised within this thread, the "bad" thing is that it represents an unplanned, uncommunicated form of pressure by a dive pro, to keep a low-on-air diver at depth, simply for the convenience of not having had to apply a proactive solution for ensuring that the divers under their supervision had sufficient air for the planned dive.

3. Specifically in regards to air-sharing as a diving (not emergency) technique for extending bottom time - the primary issue that I see is the potential that a diver is low-on-air at depth. That is "bad". It is the response to a diver being low-on-air underwater that concerns me. The prudent, universally agreed, response to a low-on-air situation being to make an immediate buddy/team ascent (sharing air if necessary). Choosing to deviate from that response, to encourage the low-on-air diver to remain at depth, IS A BIG THING.

And yes -- I have shared air for kicks, I do share air for kicks and I will share air for kicks -- does this make me "bad?"

As an instructor, I encourage lots of air-sharing practice. Familiarity breeds confidence and competence. Repetition works.

In the last few weeks I taught a wreck-sidemount-tec40-tec45 combo of courses. Each of those courses included many air-sharing drills as a standard. I went beyond the minimum standard - we did a LOT of air-sharing, amongst other things. We did air-sharing until it became common-place... to the point of being boring. We did air-sharing, without warning, until the point that the student was constantly aware and prepared for that contingency. That is obviously not "bad".

However, I still wouldn't consider putting a 'real' low-on-air diver onto my gas, for the purposes of extending their bottom time. I believe that it encourages complacency in a situation that should otherwise be recognized with alarm. It encourages a sloppy mindset and the taking of short-cuts. I believe it teaches a negative lesson - where respect for gas management and the seriousness of being low-on-air is undermined.

As I said earlier, I don't believe that there is a fine-line between practice (or for kicks) and the reality of a low-on-air scenario.

Sharing air isn't bad... but being low-on-air is very BAD.

 

[t4e]

This practice is a bad idea, unless it is for practice in a controlled situation.

I see DM's do it.

They are intentionally creating a " life - bond " . The diver believes that they are giving them life. The DM becomes their " Dive God ".

The divers fall in Love with their DM's, because they gave up their Life ( air ).

They only feel safe diving with their " Dive God ".

This practice creates dependency at the highest level!

Bad Idea.

actually not at all, my feeling all along, as well as my husband's, was that this was not supposed to happen
in training i was told air sharing is an emergency procedure

Typically 2nd stage regulators work on an intermediate pressure of 130-140psi, which means that below that level performance will be significantly degraded. 200PSI is basically an OOA diver and from a safety perspective is really cutting it too close. Also SPG's at the low end of the scale can be less accurate so you may have had more or less air that your gauge indicated. Did you do a safety stop? That low on air should have at least meant an abbreviated ss. I have stupidly run that low before as well (intentionally stayed long to get a few pictures, which was obviously not a good excuse), so I'm not jumping on you, just making sure your aware of the situation so you can approach what happened with the appropriate degree of concern. Your husband should have still signaled his pressure to the DM, particularly when it became obvious that the group was not going up to the safety stop. If the DM isn't aware of his divers gas reserve, he can't take action to ensure the dive is conducted safely for all his divers.

we did a 3 minutes safety stop

i am fully aware of the fact that the SPG can be inaccurate at low levels and that was another reason i was worried
my husband didn't signal his air because as i said the plan was that we would make our way up as soon as one of us was at 700psi, it not an excuse by any means but definitely lesson learned for future

As your signature states: 'Criticism may not be agreeable, but it is necessary".
I would say that until you have enough experience to decrease your gas consumption, you shouldn't be diving very deep. You haven't stated how deep you were, but if it's true that the DM had 2000psi when you were down to 700, it would seem you were either too deep, moving too fast or most likely, a combination of the two.

If you were breathing that fast, 200psi would have been a couple of mins away from empty. Please don't take this the wrong way, but I would limit your depths to between 30 and 50ft until you get your consumption down. It's OK to ask operators for shallow dives, you get more time in the water thus gain more experience faster and there's less stress for everyone involved.

There have been recent threads about how to improve breathing control.

please feel free to criticize, the reason i started the thread is because i want to learn
we were at 54ft for 40 minutes
the DM is an extremely small guy, and from what i know apart from experience a persons lung capacity also plays a role in their air consumption, also that is what he said i did not see his SPG

that is exactly our plan for now, go no deeper than 50ft, and its one of the reasons i have contacted so many dive shops before committing to book something
i wanted to go to dive sites no deeper than 50ft-60ft so i asked each one if that is something they go to, the point i wanted to get across to them is that we do not wish to go to bottomless places and stay at 50ft, i wanted sites where the bottom was at 50
i also questioned them about the ratio of DM's to divers
we realize our limitations as new divers and want to ensure that we have a safe dive as much as we can

T4e

Sorry misread details of your post. I think the air share was fine. But both of going to 200 psi is cutting very close unless the last part of the dive was very shallow.

Consider doing a search on "rock bottom" here.

yes, i realize it was cutting close and i guess thee replies in this thread confirmed my initial feeling