Sharing air to extend bottom time

[Fish-R-Man]

I see two major issues with the dive scenario that you described,given that you and your husband are both new divers....

1) When you indicated to your DM that you had exceeded your lower limit of yourair supply by reaching 500 psi (I would imagine at the depth you were in, thedive plan would have called for 700+ psi as the turn point) The DM should havecalled the dive at that point. By sharing air, he could have kept your back gasas a reserve in case of an issue on your accent.

2) When you were safely on his air source, I can't believe that your DM didn'tverify your husband’s remaining air supply. In most cases women seem to havebetter SAC rates than men. I would have expected him to have the same or lessair than you did in this situation.

If your DM would have known that your husband was also at the turn point, Icould not imagine that he would not have called the dive at that point. Youalso have to remember that anyone at any time can call the dive. If you reached500 psi, that should have been your first cue. If you were uncomfortable withthe air share, that should have been your second cue. If your husband was at700 psi at 50', that should have been his cue.
I really don’t see where this scenario could beconsidered “good practice”.

 

[TSandM]

On air NDLs, 20mins at 30m shouldn't be something requiring air sharing IME.

Nitrox.

 

[LaMissJude]

1) A DM/guide sharing air with a diver for extend the diver's bottom time is wrong in my opinion, a lot of posters have said it.
I've seen that happening a lot in the Red Sea, I was even asked to do it by the dive center I was working for at the time. Tried it a bit (1st job) and realise how stupid and dangerous it was, as I couldn't focus on other divers. I prefered to dive shallower whenever I had a "big breather", and managed pretty much all the time a minimum of 45min dive to one hour, as well as explained to the "big breather" how to breathe/stop swimming/control his buoyancy...

2)

How deep are these dives you're doing?
Again, I can't see how a truly experienced diver would even need to air share on a recreational dive. On air NDLs, 20mins at 30m shouldn't be something requiring air sharing IME.

And finally 3)
Some divers on this thread seem to find this practice perfectly acceptable. They are certified, and seem to be experienced to very experienced. During their dive, after all, they can do what they want.
Still, it is not a practice I like to see during my guided dives, as things can go wrong really quickly, and it is a bad example to set for less experienced divers.

What I find disturbing here, is to say on a public thread that everybody can read (newly certified, "vacation divers") that air sharing is an acceptable practice to extend bottom time.
And eventually some can just think that after all, it is an acceptable practice.

I understand that not every diver can dive as much as they would like (location, work...) and I'm not here to judge that, but it has also an impact on the level of comfort, breathing etc.

With the different levels I've seen underwater (as a diver, as an instructor and as a guide) many, many, divers could end up having troubles doing that. Starting with bad gas management, to bad buoyancy management, to having potentially 2 divers in trouble.

The fastest breather lead the dive time...
Up to the dive operator to make balanced groups whenever it is possible, to fill properly the tanks, and if possible, to have different tank size (price of the tank and location might make it complicated though)...
I also happened to "exchange" divers with other guides (explained during briefing and agreed with the other guide) and the slowest breathers can enjoy their full one hour...

 

[t4e]

I see two major issues with the dive scenario that you described,given that you and your husband are both new divers....

1) When you indicated to your DM that you had exceeded your lower limit of your air supply by reaching 500 psi (I would imagine at the depth you were in, the dive plan would have called for 700+ psi as the turn point) The DM should havecalled the dive at that point. By sharing air, he could have kept your back gasas a reserve in case of an issue on your accent.

i guess you missed some of the details
-the dive plan did call for surfacing when first one was at 700
- i did signal to him when i was at 700 and that is when he made the decision that we share air for a bit, however i have completed my ascent and the safety stop on my own air so when i reached the boat i had 500psi left

2) When you were safely on his air source, I can't believe that your DM didn't verify your husband’s remaining air supply. In most cases women seem to have better SAC rates than men. I would have expected him to have the same or lessair than you did in this situation.

my husband had about 200 more when all this occurred

If your DM would have known that your husband was also at the turn point, I could not imagine that he would not have called the dive at that point. You also have to remember that anyone at any time can call the dive. If you reached 500 psi, that should have been your first cue. If you were uncomfortable with the air share, that should have been your second cue. If your husband was at700 psi at 50', that should have been his cue.
I really don’t see where this scenario could be considered “good practice”.

while sharing air i have asked the DM if we're going up and he said "in a bit"
i know anyone can call a dive and we did at 700 according to plan, but please tell me what else should we could have done different, refuse to share air, start going up on our own?
i have stated earlier that my discomfort was not coming from sharing air but rather from the fact that i did not know what is going on, since i expected that as in previous dives he would deploy the sausage and this time he didn't, once he motioned to me that we will surface in a bit and then when i got back on my own air and we started the ascent i was OK, except for the darn fish that tried to nibble at our gear all the way up

please don't get me wrong, i don't think the DM had any intention to endanger our life at any point, however the lesson learned here is that in the future this will be something that we would make sure to discuss as part of the dive plan
perhaps calling it "good practice" is not accurate but rather a "learning experience", unfortunately training can't prepare one for every situation in real life and i look back at this as a real life "lesson"

 

[Divealpha]

I think being used to sharing air is an important skill. My buddy/wife does it every now and then if one of us suddenly have a bit less air than the other..
It depends on the circumstances. We always keep the gas reserve within limits, though. I'm just glad we had DM's/Instructors who taught us this early so we're feeling safe doing it. The first time we had a DM diving doubles & longhose, who offered me his reg.(My wife didn't understand why he offered her his reg), and after the dive he told us he did it also to get his dive a bit longer.
Next time was abroad, guess we had 20 dives then, and both me & my wife breathed on our DM's regs(a luxury, our own DM's for ourselves).
They solely did it so we were able to get back to the shore instead of surfacing and have a long swim back.........
So, later during AOW, we where diving Nitrox, I used my air pretty fast during a wreck dive with strong currents, and started back to the rope with 70bar left(buddy 90), the DM just took my reg without warning, and gave me his own(air 21% by btw). Since we already had experience in this, I had no problem with it, except that I was on Nitrox, & was planning to borrow from my wife when we where doing our safety stop.

Once my wife experienced free flow on her reg when switching, but again, since we were confident sharing, she solved it herself, and we could continue the dive. We ascended a bit though, so now we're keeping an eye on the depth too , but this time, the DM's told us that this was not allowed....

So I can see why the issue brings up different views... Been diving a lot on vacations(at least two times a day, weekends off), and have even seen DM's sharing air with divers after 15 minutes(and that was a diver with a DM certification), so we could get back to the boat..
It's all about circumstances, & my SAC differs..., and mostly the dive centers only have one size tanks.
We'll keep on sharing, but if we have less than 70bar, we're heading for the boat/shore.

 

[Peter Guy]

Just to keep this thread alive....

As I wrote earlier, this is not a "common" practice but I do find it an acceptable one. The last time I remember sharing gas to extend my dive was in Sept. 2008 in Tahiti. As it turned out, there were three "guides" and just the two of us

According to my notes, the max depth was 85 feet, avg depth 48 feet, dive time 52 minutes. I started the dive on an AL 80 with 2810 psi and ended the dive 460 psi. My notes state I "sucked on Lynne's gas for about 5 minutes" and from the dive profile, probably when we were cruising around 60 feet during the middle of the dive.

Safe/unsafe -- good/bad/indifferent -- those are the facts, you decide.

 

[RTee]

Peter, when I did it in Cuba using 80 cft steel tank, we turned a 20 - 22 min dives into a 49 and 47 min dives respectively. First one max depth was 89 ft, avg 62 ft and I got back on the boat with 1000 psi. Second dive was max depth 100 ft, avg depth 63 ft and I got back on the boat with 600 psi. In both cases, we had the air hogger rotating within our group (five divers altogether) as we all knew each others, had done several dives together both locally and on vacation and were very comfy in the process which was initiated slightly below half tank. Matter of fact, had done it before with same individual on two occasions on local dives to prevent longer surface swims in a busy area.

BTW, in both situations, dive buddy and/or DM, we need to be careful before establishing recipes to be followed blindly. As I mentionned before, I saw a DM having to do so in Bonaire as part of a drift dive because one individual was litterally going to ruin it for the entire group. He was an outsider who just ended up tagging along on a boat with our group who was putting the finishing touch to a two week diving trip in Bonaire. It was very clear in the DM's mind that none of us required chaperone as we were all able to take care of each other (as we were all diving in pairs or threesome anyway and he knew us from before. As a matter of fact, it does make the DM job pretty darn easy when diving in such an environment...just concentrate on the unknown as the others will take care of themselves and will also cover your six if need be.

As for doing so as a dive buddy, there is a diffference doing something like that with somebody you know well and dive with often or regularly and an insta-buddy that you just got paired with. In both cases for me, it is a no brainer even though the end result may not be necessarily the same.

 

[diverrex]

From all this I wish more dive centers would offer a few more 100 cu ft tanks. I've gladly paid an extra $5 a tank when they are available. A 100 usually puts my air consumption equal to my wife on an 80. After paying a bunch of other travel costs it's shame to have some dives limited to only 45 minutes instead of an hour because only 80s are available. Dive centers that only have one boat with all levels of divers together and also have a policy of everyone ascending together when anyone is low on air should definitely have 100s for the heavy breathers.

One thing I've learned to do when only an 80 is available is before assembling my gear I put my reg on the 4 tanks my wife and I will use. I then take the two tanks with the best fills for me and use the best fill of those two for the first dive. Helps a little a least.

 

[idive2]

I saw this on my one trip to cozumel on two different trips. The reefs are deep and the air
does go a bit faster. We were about thirty minutes or so on a deep drift dive and I figured
we would be wrapping it up shortly. This is when a guide did the air donate thing and I wondered if
this was being done for the benefit of the group or for the benefit of the dive guide ? My second thought
was " this guy dives every freakin day is he really concerned about cutting his own dive short ? "
I can't say I know his reason but I have seen this in other circumstances which also seemed that
it may have been the guide not wanting to come up. We have drift divers here on the florida reefs that
need there sixty minutes plus at sixty feet or they feel they have not got the dive time they wanted.

 

[LostWithNoWater]

My quick $0.02...

The sharing of air should only be done to get the diver out of a rough situation, such as highly trafficked areas, rough surfs, etc. It's not a safe practice, and I don't recommend it. This practice of sharing air should not be preached, instead people need to work on their gas consumption thru streamlining, mechanics of breathing, etc.

My observation when a DM practices this is not of a good opinion. There's too many "What if?" scenarios that can arise. If an emergency situation did arise, the reaction time for a DM, or anyone for that matter, would be delayed. As we all know, seconds can either save or kill.

Now, with that being said, people will do what they want and you can't stop them. If anyone is going to do this, please take in account that extra bottom time thru sharing air, isn't worth the potential consequences. The marine life and water will be there later.

Safe diving everyone.