An interesting dive

[Ice Mike]

I don't know where this "the dive is over" stuff comes from.

I think most agencies train something in the order of: If a diver is ooa then you both go to the surface in a safe manner.
People who don't think it through then seem to translate it into: If air sharing you go to the surface in a safe manner.

I think it has a lot to do with teaching people to follow standards without teaching them the reasoning behind those standards.

Without knowing the reasoning behind the standards it is difficult to accept other ways of doing things. Since you don't know whether the different way still covers the reasoning behind the standards that was deviated from.

This is not specific to scuba.

Just MY (and only MY) 2 bar worth

 

[peterbj7]

What's going on, Mike? Another thing we agree on!

 

[carolrose]

When I reach safety reserve (rock bottom) the dive is over, period. If, for some reason, I have an equipment malfunction or gas loss and have to go on someone's long hose, I am by definition below safety reserve, and the dive is over, period.

HOWEVER . . . Peter's SAC rate is about .6; mine is .4. If we are diving in the tropics on the same sized tank, Peter's gas consumption will cut our dive short while I still have a lot of excess in my tank. For that reason, and only EARLY IN THE DIVE, Peter will go on my long hose for a while. I not only don't think that's dangerous, I think it's a good thing. We get the practice of air-sharing and swimming while sharing gas; both of us have oodles of our own gas, so even if somehow we got separated, there's no problem. And we end up with equalized gas consumption.

We have had problems with DMs seeing us do this (even, sometimes, after we have explained that we are going to) and literally freaking out, and I've had a PADI instructor tell me that he felt it was unconscionable, because once you are sharing gas, the only thing you can do is an immediate ascent. But we're CAVE DIVERS . . . If we share gas, we swim out. I think it's good to practice that.

I've done the exact same with my husband and see no problem with it. I have a long hose, so we generally just hold hands and swim along with no issues. We always let the DM know ahead of time and we do it early in the dive, so we're both going to end the dive with similar pressure left, instead of him at 500 and at double that or more.

 

[Gombessa]

If the situation were understood/planned, I think it's fine. If you're on a vacation dive with a DM, I think it's uncommon enough where you'd have an obligation to inform the DM (after all, his job is to make sure everything goes smoothly).

But if it were unexpected - if a buddy or random diver signaled OOA, accepted my hose and then indicated he wanted to continue the dive, I'd flatly refuse, and insist we surface even if it were "common practice" in the area. If you don't give any indication that you'll do this, throw an OOA and take my gas, I'm going to assume the worst and thumb the dive. If you don't like that, you're perfectly welcome to either work it into the plan with me next time, or not dive with me.

If I was the air hog on a dive and the DM wanted to share air to continue the dive, I'm not sure what I'd really do in the situation, but my preference would be to surface individually when I reached the end of my usable gas, and let the rest of the group continue the dive. If it was a "we all go up when the the first person runs low" dive, I'd definitely be feeling some pressure.

 

[mkutyna]

Question:

Why is it most all the dive boats use AL 80 tanks?
Being a newer diver and a bit of an air hog I have gone to larger tanks of my own.
Al 100's don't cost much more then the 80's yes they are big but most guys over 6' can handle them with no problems

It's probably already fairly annoying for dive ops to handle two different sized tanks in the AL80s and AL63s. Add a third size with the AL100s and that's a big pain in the but. Not to mention that I'm pretty sure the AL100s are a larger diameter which would require replacing a huge number of tank racks on boats.

 

[DeepDiver36]

I have found this to be a very interesting thread. I value the opinions presented here and can see how different training and life experience has molded those opinions.

I think most agencies train something in the order of: If a diver is ooa then you both go to the surface in a safe manner.
People who don't think it through then seem to translate it into: If air sharing you go to the surface in a safe manner.

I think it has a lot to do with teaching people to follow standards without teaching them the reasoning behind those standards.

Without knowing the reasoning behind the standards it is difficult to accept other ways of doing things. Since you don't know whether the different way still covers the reasoning behind the standards that was deviated from.

I think ICE MIKE has hit the nail on the head. We fear what we do not understand and our training is drilled into our heads. Might it be as simple as it is a topic of diving that is never taught or clarified in class and since it is so closely related to OOA situations that we frown on the practice?

Thanks all for your opinions on this. As I said, I found this to be very informative.

 

[MikeFerrara]

If I was the air hog on a dive and the DM wanted to share air to continue the dive, I'm not sure what I'd really do in the situation, but my preference would be to surface individually when I reached the end of my usable gas, and let the rest of the group continue the dive. If it was a "we all go up when the the first person runs low" dive, I'd definitely be feeling some pressure.

I don't think diving in packs, heards or flocks ever really works well.

 

[Papa_Bear]

Never go beyond your ability! If you want to fill lift bags or blow bubbles with your usable air its yours! DMs if comfortable sharing usable air then I see no problem, you can't dive with all contingencies in mind otherwise every dive would be a tech dive and no one would dive! It is accessible risk! What is a "pack"? And why would you put someone down for diving where it's required? Don't go to Cozumel then! But guess what hundreds of thousands do and will continue to do so, ignoring them doesn't change a thing! If you and your buddy want to practice buddy breathing then do it! We are headed for SCUBA police if we don't get a grip! In most places where there are guided dives the DMs are instructors as well and if the instructor wants to demonstrate buddy breathing then I say great. It has to be judged on the circumstances at hand and not a inflexible rule! There is no Common Sense anymore so I wont appeal to it!

What we have to teach is water comfort and skills! We need divers to dive more often and many problems will solve themselves!

Aluminum 80's are easier to ship, cheap, and most operators feel it is harder for their divers to get into trouble with 70 some cubic feet of air!

 

[Gombessa]

I don't think diving in packs, heards or flocks ever really works well.

Tell me about it. But these are the situations in which I hear this "DM-airshare" situation tends to pop up - several divers in a group, and everyone has to ascend when the first person runs low.

If that weren't the case, people would just dive their own profiles and ascend in buddy teams as necessary.

 

[MikeFerrara]

What is a "pack"? And why would you put someone down for diving where it's required? Don't go to Cozumel then!

Directed to me? A "pack" is a group like a "herd" or a "flock". I didn't put anyone down. I stated an opinion on the functionality of diving in a "pack". I have no plans to go to Cozumel or anyplace where following a DM in a pack is required.