jbd:
As a point of discussion I would like to hear what the arguements are against buddy breathing when the people involved are trained and competent in the skill. I don't want to hear things like, one should never get in that situation yada yada yada. The scenario is that the two divers ARE in the situation where one is OOA for whatever reason and they are at a depth of 120(salt water or freshwater) and there have been enough equipment failures or whatever so that there is only one regulated source of air/gas.
Because PADI says you should be doing a CESA instead?

OPPS! Did I say that out load:shakehead.
After all their order is
Normal Accent
Buddy Assisted normal accent
CESA
Buddy Breathing.
Now I don't know about you, but personally, I failed (intentionally) when asked to put these in order as I personally think that the chances of a safe (non bending experience) ascent while performing a CESA, from any depth is questionable, and believe that if there is sufficient air in buddy's tank (which there should be if you've done proper gas planning), that the chances of both making it to the surface safely are greater using buddy breathing (assuming that merely donating a secondary is not possible).
Now some might argue that buddy breathing has the potential of creating a potential second victim scenario. That belief is predicated on the assumption that both divers are at risk when buddy breathing so the practice is discouraged. As the practice is discouraged it is not practiced sufficiently enough for the student diver to become proficient enough in the task. The cycle is self perpetuating.
I put forward that if the drill were to be taught and practiced the student would become proficient in the task to the point where buddy breathing would be no more of a risk than donating a secondary.
IMHO, students are taught to use a CESA before attempting to buddy breath for training liability reasons only. Take an average OW check out dive. Most are done in thirty feet or less of water, where a student can simply blow for the surface. The agencies probably figure that if an OW student panics or has a problem instinct will take over they'll head up anyway, so they might as well be taught how to do it a safely as possible.
I personally think this wrong headed, and being a diver who has had a serious OOA at depth (95 feet) it's a good thing that I personally put CESA in the bottom of the list.
Some will argue that buddy breathing is inherently dangerous and should not be taught in OW at all, but rather later after a student has become more proficient in other skills like controlled ascents and buoyancy control. Those who espouse this, are also predicating their stance on the assumption that there is not enough time in an OW to master the prerequisite skills needed to perform buddy breathing safely, but then will also argue that the OW course need not be lengthened......yet another self perpetuating cycle.
The solution, from a pure training point of view, is actually quite simple. Increase the length of the OW course and the number of OW dives, to allow the average student to become proficient in the fundamentals like buoyancy control and ascents to the point where buddy breathing can then be taught and practiced not only kneeling on the bottom, as it is now, but also while ascending properly.
Again it all goes back to the fact that the agencies are more concerned with the volume of divers they can churn out, not the quality
BTW, if youre at 120 feet and your buddy is not around, you failed to practice proper buddy diving so a please pass on my regards Mr. Darwin when you meet him.