Sharing air to extend bottom time

[SeaCobra]

Air sharing in itself is not a bad thing, however the practice of sharing air to extend someone else's bottom time is an unsafe practice and to promote or condone it in a public forum read by a lot of people is something you should be very careful about. I will double check my Instructor Guides but I am pretty sure I will not find this procedure demonstrated. DevonDiver has already done a very nice job of politely stating how I feel on this issue.

And btw- I am not described as a NAUI Course Director, I am one. Not to mention a NAUI Tec Instructor. If you'd like I can scan in my credentials for you.

Scuba diving is a tremendous amount of fun and excitement. And for the most part it does take a lot of hard and fast procedures to be safe, but the ocean can be a harsh mistress and there are a few areas that really need attention. Gas management, proper weighting and emergency procedures come to mind. If you are low on air I will gladly share what I have, I will end the dive and ensure we have a safe ascent. I will even dive with you knowing that our dive may be a little shorter than others, but I will not engage in sharing air so you can look at the pretty fish for a few more minutes.

 

[dumpsterDiver]

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.



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




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.



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.

I think you are grasping at straws with this stuff.... Besides EVERYONE said that this type of air sharing (to extend the dive) should be done BEFORE anyone gets low on air..

Hell, my brother and I used to switch scuba units halfway through the dive to extend our bottom time on 100 ft drift dives ...

 

[Mr Carcharodon]

Of course air sharing should be a total non-event. Things that you do with regularity are non-events. So by all means do it every dive or at least until you get tired of doing it. The idea that most divers cannot be trusted to put a regulator into their mouths and breathe is just bizarre, and is advocating a state perpetual incompetence.

 

[DevonDiver]

I think you are grasping at straws with this stuff.... Besides EVERYONE said that this type of air sharing (to extend the dive) should be done BEFORE anyone gets low on air..

What people say here on Scubaboard doesn't necessarily reflect what happens in reality.

'We', even the most novice diver who is a member on the forum, represent a very specific and distinct demographic within the scuba community - differentiated by, if nothing else, a substantially above-average interest in the activity and desire to further our understanding and enjoyment of scuba diving through participation and education. The vast majority of trained scuba divers do not participate in any form of diving community, debate, discussion or informal education - they just get themselves wet on an infrequent basis and enjoy seeing the fishes.

The issue I'm addressing is what the OP, and subsequent posters, have referred to in respect of the conduct of some divemasters, who put low-on-air divers onto their AAS for the convenience of not having to prematurely cease a dive.

Further to that, if a dive team know that there will be inconsistencies in their air consumption, then why not address the issue properly, by ensuring each diver has an adequate air supply (sized cylinder) for the dive which they are planning?

Sharing air between divers (when not otherwise L-O-A) can, at best, be seen as nothing more than a sloppy reaction to the root problem of inadequate gas management, insufficient dive planning and the selection of unsuitable dive equipment to meet the planned dive objectives.

Hell, my brother and I used to switch scuba units halfway through the dive to extend our bottom time on 100 ft drift dives ...

That's a valid solution, albeit one that demands a certain level of competence and comfort in the water - something not shared by the majority of divers.

Having said that, whilst being a valid solution, it may not be the optimum one.

I'd suggest that the optimum solution would be more effective dive planning (depth/duration) coupled with efficient gas management (calculating individual air consumption)... to provide foresight of each divers precise gas requirements.... and then addressing those requirements through the selection and use of appropriate equipment - in this instance, the use of cylinders which provide a gas supply equal to, or exceeding, the individual diver's planned consumption.

A prudent and professional Divemaster, who wants to ensure group integrity on a planned dive, could make the effort to implement that optimum solution.

Likewise, an experienced and safety-orientated individual diver/buddy pair/team could implement that same optimum solution for themselves.

The reason not to? It's easier to take short-cuts, than it is to do something properly. Many would call that laziness.

 

[supergaijin]

As DD has pointed out, there seems to be a different approach among established buddies to share air knowing that one dive will consume more than the other. Thus at the start of the dive, after initial descent, the divers share air until an agreed point and then switch back to their own air supply. What you do on your own dives is up to you IMO. However if diving in a group, all divers should be made aware of the intention to share air at depth to avoid confusion. Even then, I'd rather not see it on my guided dives. IMO there is enough workload at depth already without introducing another one.

To all DMs, I really wish you wouldn't do this but rather attempt to educate the diver who is breathing hard (after the dive). This is normally seen as just part of the job, to further educate people and increase safety and enjoyment for all.

 

[redacted]

I have done such an air share at the beginning of a dive - all planned in advance.

One of my dive buddies just had is adult son certified and we decide to do a local dive that was not deep but would tank an hour. We knew the new diver was not going to make that on a single Al80. So we worked out a gas plan that called for 3 Al 80's ans an Al 63. I slung the 63 and did the first leg UW, breathing the 63 and towing the flag, to a way point at 30 ffw. Father and son joined me and the father took the flag ande we put the son on my slung 63 with him holding on to my side where we both could see the SPG. He had his primary in his hand, ready to go. We did the next leg to our destination at 40 ffw where the son switched over to his own full Al 80. We explored the destination and then navigated back to the shore entry point with everyone having an adequate gas reserve. I was not totally sure the new diver would be able to handle the plan but we could abort at any time. He had no problem at all and executed as planned.

Every dive has a certain element of danger. I don't believe our specific plan added to that element in any way.

 

[dumpsterDiver]

The argument of lazy and improper planning is pretty weak. When people go on vacation dives, the standard tank is an 80.. one guy weighs 240 and the wife weighs 125.. Their size differential and concomitant difference in SAC and the inability to select a tank that is more suited to their respective sizes, makes sharing air for 6 minutes a viable means to extend their dive...

 

[BluewaterSail]

I see 2 scenarios being discussed but not differentiated by all posters:

1) not immediatly calling the dive when one diver is low on air, or turning when the first person reaches the turn pressure, but rather continue as nothing happened using an air share

2) sharing air early to keep a diver from arriving at the turn pressure earlier than others.

I could not imagine anyone condoning #1, but I find it hard to be really negative about #2. In the second scenario, you always have the option of stopping the air share if anything goes wrong. In the first situation, you are increasing the risk every moment. I have seen the first scenario with DMs on easy guided shore dives, and it really scares me. I was offered to do a scenario #2 (diving with someone who I didn't know well, but knew that his SAC was way better than mine) and I did not agree. But I think if he was a regular buddy, I would have done it, especially on an easy dive, without much regret.

 

[diverrex]

When I first started diving I remember seeing a husband and wife share air and I thought that was wrong to do so just to extend the dive, sharing air was for emergencies only I thought back then. Now as a more experienced diver and reading through all these posts I can see the value of two divers sharing air early in the dive when they know they have differences in consumption which is often typical with a husband and wife. I dive 2 - 3 times as much as my wife but she still uses way less air than me.

I just don't see the big deal of sharing air early in the dive, how is that really going to decrease my and my buddy's safety? In other threads many divers advocate sharing air every dive as "practice". Well if that's okay why is it any worse to do it but just to do so for longer? Just because the intent is different? I don't buy that. If sharing air is such a dangerous activity then I'm not sure people should be practicing it.

The idea that sharing air somehow represents "bad gas management" or "improper equipment selection" just doesn't take into account that sometimes all you get is an ALU 80 and there isn't an alternative for a larger tank or doubles, etc.

As Peter said what can really happen bad? Your buddy's reg comes out of your mouth? I can do reg recovery of mine, a simple procedure, and if it's early in the dive I got plenty of gas on my back.

I find it funny that this practice causes this much division between even very experienced and credentialed divers. Just goes to show that there are lots of opinions around. If you don't like the practice then just don't do it.

 

[PeterNBiddle]

I should add that never once was I low on air when I shared. Sharing with our groups was started at 900 PSI or so (in one case as high as 1200).

An emergency switch back to primary air would have been a switch back to plenty, not to a low air situation.