Sharing air to extend bottom time

[DevonDiver]

With an AL80, you have at least 13cf of gas remaining at 500 psi...more than enough for a lazy ascent and short safety stop.

By "you" are you inferring 'any member of the human race, regardless of SAC'... and 'from any depth'. If so, you may want to reconsider the statement

 

[Teamcasa]

If I see it happening during my guided dives, I have a talk afterwards to the couple involved and usually sort it out. I guess if there are only two divers, diving regularly together, the divers in question have the right to do what they want.... but I would still advise against it.

A well reasoned response.
However, as I've said previously, it's something my wife and I do, occasionally, when on vacation and it's not lazy or sloppy.

Like I said earlier, we will discuss it pre-dive and if the DM/guide has an issue with it, I would work it out with them before we splash.

 

[tridacna]

My new favorite word: "Certificated"!

 

[beaverdivers]

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.

 

[markmantei]

as i said above he had about 200 more, back up on the boat we both had about 200 left in our tanks

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.

I am in complete agreement with the other posters regarding DM's that routinely do potentially putting their customers at increased risk unnecessarily, as they will be unable to respond as quickly in a real emergency (I have seen it happen routinely both in Playa and Coz). By far the better solution is to match tanks to consumption rates (which is also done by some ops in Coz), but that is not always an option if the only tanks available are AL80's. Buddies doing this as a planned method for extending a dive, having discussed it beforehand and sharing air early in the dive is acceptable, and can be good practice for an emergency, but that is not the situation in the OP's senario.

 

[supergaijin]

i'm a noobie diver, i don't see it as the "leash of shame" until i am experienced enough to have a good air consuption

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.

 

[Peter Guy]

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

To be "Clintonian" about this, I suppose it depends on the definition of "This." I agree that having a Guide/DM share air to extend the BT of a group member isn't the best possible situation since it does restrict the Guide/DM from other, perhaps more important, tasks.

BUT, if "This" merely refers to two people sharing the same gas supply for a period of time, then no, it may well be a perfectly good idea. It may also well be a good idea for a Guide/DM to share air with a low air diver in order to get the group to a better ascent point (I'll freely admit I've done this -- shared air with a low on air diver and not gone directly to the surface because a better option was to go much shallower where there was a natural reference point for a night ascent -- at which point the diver went back onto her own (adequate) air supply and a non-eventful ascent occurred -- note, it might have been better for the diver to have watched her supply more closely but she didn't).

As with so many things scuba, the most correct answer is "It depends."

 

[DivemasterDennis]

How wonderful to learn other people do this besides me. It was a dark dark scuba secret in my life (until now) that I have been known to breathe off my wife's tank on occasion, because on most (but not all) dives she uses about 30% less air than I do. I refer to her as my "spare air." However, I would not do this as a DM for purposes of prolonging a dive. If I had a low-on-air diver and I had an abundance of air, I would perhaps have them breath off my tank as we returned to our exit point to allow them to preserve sufficient independent air for them to ascend and do a safety stop. In all my years, however, I believe have done this only once.
DivemasterDennis

 

[SeaCobra]

The reason it has been a deep dark secret is that in reality we all know that this is a bad, unsafe and inane practice. I am a bit stunned by the number of folks that think this is OK, especially with a couple of moderators and a "super poster" all admitting to this. 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.

 

[JamesK]

Not a fan of this practice personally. However comma (yes, spelled out for dramatic effect) a DM doing this to get someone back to somewhere that will avoid a difficult surface swim or egress is not a problem IMO. For instance, one of my favorite dive sites here is called "The Slot". Dun dun dunnnnnn! Anyway, at "The Slot" DUN DUN DUNNNNN! the entry and exit is in a shallow pool. To get to that pool you walk out in knee deep water, then drop off a ledge to this chest high pool. Going out from there requires going between a 4 foot wide "slot" in the rocks that goes from 4 feet deep down to 20 feet deep on a slope. The surf pounds through there horribly. It usually shoots you out like a rocket, and you have to pull yourself in. Trying to surface swim through this coming back would be brutal. So sharing air on the way in would be much easier. Especially on a long hose. That is why I preach the long hose here. Although every thinks I am nutty. Well, Ok, I am nutty.

For a DM to do this simply to extend the bottom time of customers I think is a big mistake. As others have said, it takes him away from his real duties. Someone doing this on a easy peesy cheesy dive, well, that is debatable. A team that dive together a lot, I am slightly tolerant of, although I discourage it. New divers getting in to this practice = no good.