When to donate air?

[sinidive]

An example scenario where it might make sense:

- A chill shallow holiday reef dive, turn pressure has been agreed to be 100 bars.
- We are circling the boat (or it is a drift dive) - not having to swim the same distance back, no overhead and no deco
- Both divers are comfortable sharing air and want to do it
- Configuration (e.g. long hose) makes air sharing convenient
- Practicing without an emergency is good
- I have 160 bars, my buddy has 120 bars
- Sharing air to extend dive time is ok in the group
- I'll share air with buddy till we are both at 120 bars, thus extending total dive time for the group

Some concerns:
- Is my buddy's SAC abnormally high? (is there an underlying problem)
- Is there a return leg where buddy's SAC would be a problem?
- Don't cause a surprise to the team/group

 

[Still Kicking]

One time to donate gas is when it is asked for ... not negotiable. Debate the finer points of the situation at the surface.

But using gas donation to extend a dive ... I think it's a bad idea to do it as a matter of routine. It's called SELF CONTAINED underwater breathing apparatus for a reason.

There are better solutions to managing different consumption rates (bigger tank, pairing divers with similar SAC, shorter/shallower dives) and putting two divers on one supply for an extended period on a regular basis is setting up a real emergency situation at some point.

Eg. DM puts newbie low on air diver on his long hose to extend their dive. Then a second diver in the group comes and signals OOA. Then what?

 

[Imla]

Also keep in mind that donating early, when everybody have low stress, clear minds and rational thought are risk minimizing behaviour.
Donating early will also keep the low on gas diver in control of their own buoyancy. Having enough gas left for a possible separation and eventual establishment of positive buoyancy on the surface is smart.
While I am torn about using gas sharing as a tool to extend dives, using it to keep inexperienced divers from having to surface early, potentially in zones of boat-traffic, current or other places not very suited for anchored boats to retrieve a diver.

 

[happy-diver]

Scuba Police offence No 3: More Dumb Diving, and talking
First offence: Suspension of diving licence for 3 months carried over if committed within 1 month of season end

 

[halocline]

If you are diving with a buddy who has realized that he does not have enough gas to safely surface, and you have enough for both of you to safely surface, then yes you should donate gas to him before he runs out of air. Obviously it is preferable for no diver to be completely out of air while submerged.

There are lots of variables in this scenario. One is, how is this communicated? If your buddy gives you the OOA signal and you don’t share air with him immediately, I hope I never have to dive with you!

But lets say he simply shows you his SPG or uses hand signals to indicate he’s low on air. At that point, if it were me, I would absolutely start sharing air before the situation gets any worse.

 

[DrWilliam]

Weird to me people are saying things like share air "when the person asks for it" and "If your buddy gives you the OOA signal and you don’t share air with him immediately, I hope I never have to dive with you!"

I never said ANYTHING about refusing to donate air to someone giving the OOA signal. My question is there scenarios where it is more safe to share air with LOA diver.

And then someone said to donate when person gets down to 700 psi ?

My gas planning says I can do a full and safe ascent with a stressed SAC from 100 feet if I have 700 psi. Because my plan is to begin this ascent from 100 feet WELL before being at 700psi, I would consider myself LOA if beginning the ascent with 700 psi, but but WHY begin donating? Let's assume open water. No overhead. I'd rather stay together as buddies and donate if needed at the safety stop if I run out (or maybe if down to 150 psi or so).

 

[Still Kicking]

Weird to me people are saying things like share air "when the person asks for it" and "If your buddy gives you the OOA signal and you don’t share air with him immediately, I hope I never have to dive with you!"

I never said ANYTHING about refusing to donate air to someone giving the OOA signal. My question is there scenarios where it is more safe to share air with LOA diver.

And then someone said to donate when person gets down to 700 psi ?

My gas planning says I can do a full and safe ascent with a stressed SAC from 100 feet if I have 700 psi. Because my plan is to begin this ascent from 100 feet WELL before being at 700psi, I would consider myself LOA if beginning the ascent with 700 psi, but but WHY begin donating? Let's assume open water. No overhead. I'd rather stay together as buddies and donate if needed at the safety stop if I run out (or maybe if down to 150 psi or so).

You titled the thread "when to donate air?"

 

[DrWilliam]

You titled the thread "when to donate air?"

Aha! Ok, I see where people are coming from then. Yes, I know, donate when someone says OOA.
But now that we're on the surface I was looking to debate the finer points.

 

[dmaziuk]

Aha! Ok, I see where people are coming from then. Yes, I know, donate when someone says OOA.
But now that we're on the surface I was looking to debate the finer points.

Finer points: dive with your wife and donate when she says so. Or else. The rest of the time: dive solo.

 

[NW Dive Dawg]

I think that donating to any diver who is OOG and signaling OOG is a no brainer..

Another scenario I can see for donating is at the safety stop. For example, I just returned from Little Cayman / Reef Divers and they actually have some fairly conservatives rules....... and depending on which crew you get can be 100% strict about it. One of their rules is that every diver has to be BACK ON THE BOAT with NO LESS than 500 psi........and they are actually checking gauges and computers to confirm that. They do have a hanging 2nd at 15ft but make it clear that it's for emergency use only.

So if my buddy and I arrive to our SS and he has 600 psi and I have 800...or visa-versa then we can share to avoid the law enforcement hassle...

For the record, that need to share never happened on LC because their depth and time limits are also very conservative.