Planned air sharing/Hose of shame to extend bottom time

[Frosty]

I see the point you guys are making. Ive done almost exactly this with number 2 son.His sac rate is about double mine (sorry fuzzy head this am--he uses twice the air I do).Knowing this once on the bottom we share air for 15 minutes off of my tank. This still leaves me with plenty of air and him with a full tank. That said I agree totally with tracy. I must say this is ALWAYS on "shallow" dives of 15m/45 feet or less.

I'd really rather see the diver with poor SAC using a larger tank. But, if the air sharing is consensual and a reserve is kept by both divers, it seems fairly safe in an open water environment.

The only issue I see with this theory is that if its dive one in a day then as a diver with a pretty good sac rate I'd be annoyed with a restriction in tank size just to cater for a newbee diver.

 

[DBailey]

I don't understand why a DM would claim the it is not a good idea for new diver to practice safety skills. Sure, there are safe and unsafe way to practice such skills, but why not focus on that rather than simply suggesting a prohibition?

I think the practice should be encouraged as long as both divers have an adequate gas reserve in case of an emergency. My buddy/wife and I do this fairly often before the low tank falls below 1000 psi.

But they weren't "practicing".

 

[nimoh]

I personally like the practice if both divers are comfortable doing it (and they should be). Doing this offers a chance to practice sharing gas...which is a good skill to have.

 

[Frosty]

I totally agree with this statement. However, divers must understand that this should be discussed ahead of time and both divers must keep a reserve. Also, the donating diver must be allowed to end the dive at any time. My ex-husband was a Hoover. He learned from a Cozumel Divemaster that he could share air with someone to extend his bottom time. However, he didn't quite grasp the basics of leaving everyone with ascent air + a reserve. He would grab my air and not allow me to surface when I felt it was time. This resulted in numerous occasions where he used all his air, all my air and we were forced to CESA with no air. I still believe that I got skin bends in Hawaii from this. It was very scarey to have someone use every drop of their air, then have them grab my regulator, against my preference, and use every drop of my air. I usually dive with an AL 63 because it fits my size better and I have an extremely good SAC. When two people are using that 63 and one is a Hoover that little tank doesn't go very far.

tracy--you have the patience of a saint. FIRST time someone tried that with me would be the very last time. After that they would be talking with a high voice for a week if they tried suckking my tank dry.

 

[DBailey]

I personally like the practice if both divers are comfortable doing it (and they should be). Doing this offers a chance to practice sharing gas...which is a good skill to have.

Practice should be split between the roles of donor and receiver. This is a one way "practice" at best.

 

[nimoh]

Practice should be split between the roles of donor and receiver. This is a one way "practice" at best.

I agree, but better than nothing. I also contend that it would be better to do it at the start of the dive rather than when one diver has reached their minimum gas. However, as described in the OP, I don't see anything really dangerous going on.

 

[victorzamora]

I've done it with my wife and another buddy before and see nothing really wrong with it. My wife did it with an instructor in Mx as well. The caveats I have are:
-Discussed beforehand, even if only potentially
-Done with divers of decent skill level
-Begins when diver lowest on air has PLENTY of air for both to surface
-Ends when diver donating air nears MinGas
-Creates an additional awareness to gas management
-Starts with proper MinGas calculations, even if only as a guideline

My wife is a comfortable diver that had proven herself to me and the guide we were with who started an airshare with 1000psi left in her tank, after having discussed it before hand, and it all ended when the lowest tank was at 1000psi. An AL80 with 1000psi can get any two divers to the surface from the depth we were looking at. I think having a third diver in the buddy team does nothing but help....as it would add redundancy.

I've got two problems with giving the airhog the biggest tank. First problem is MinGas calculations can start getting thrown off. Second problem is that I WANT A BIGGER TANK, TOO!! No need to deprive me of more air! I'm 6'6" with a good SAC rate, give me the biggest tank I can get....I'll worry about my NDLs.

 

[FinnMom]

I would be concerned about doing this with someone who wasn't trained to share gas on a long hose. with a new diver I would have started us up/back as soon as air sharing started.

That said, I will share air to extend time/even gas supplies or just practice the skill with divers who know how and know to expect this. i taught my daughter this back when she had a single tank and was very pleased to know that if she ever shared air by necessity it would be that much less stressful and unfamiliar. swimming while sharing on the long hose w/o disturbing each other is a challenging and interesting bouyancy control drill.

 

[nimoh]

I would be concerned about doing this with someone who wasn't trained to share gas on a long hose. with a new diver I would have started us up/back as soon as air sharing started.

That said, I will share air to extend time/even gas supplies or just practice the skill with divers who know how and know to expect this. i taught my daughter this back when she had a single tank and was very pleased to know that if she ever shared air by necessity it would be that much less stressful and unfamiliar. swimming while sharing on the long hose w/o disturbing each other is a challenging and interesting bouyancy control drill.

what is your concern about the long hose?

I think anyone that can share gas on a short hose can share gas just as easily on a long hose. This is much different that giving a diver a long hose as their own equipment without showing them how to use it.

 

[Freewillow]

+1 with Nimoh