TSandM:
I don't think Mike said he wouldn't teach such a person. He said he wouldn't go on a dive with them. The two are different.
For some reason, this question seems to have hit quite a nerve for you, OhGoDive. You're quite right that the original question I asked wasn't what Mike needed to know to dive to 80 feet. I was trying to generalize. I just think that, with all of us jumping on new divers and telling them they can't do deep dives, there ought to be some sense of what somebody should be looking for as far as what they need to DO deeper dives.
My personal feeling is that, to go deeper than about 60 feet, you should be able to put your mask on and clear it without losing significant position in the water column. You should be able to execute a competent air-share, and an air-sharing ascent with control of your buoyancy and appropriate stops. You should be able to execute a mask-off ascent with buddy support. You should understand some gas management and the concept of rock bottom, and be able to do the calculations to know if the tank you're using will suffice to do the dive you contemplate.
And preferably, you should have done enough diving to have had one or two things go wrong, so you know how you react and how calm you can remain in the face of a problem.
How's that for a set of criteria?
It's a great set of criteria.
But... (you just knew a but was coming, didn't you?)
But, what exactly does it prove that you're capable of? Dive safely to 61 feet? 80 feet? 100+? I'm not sure. Add more variables and it gets even fuzzier. Those are great skills to have, and I would never argue that someone would not be a better diver with those skills than without.
But, are those the required skills in order to do a dive to 90 feet in a strong Cozumel current? Is there a correlation between having those skills and successfully completing a dive? Are the odds higher? Probably, but I'm not sure.
And, I guess that is the nerve that got hit. It just seems that many people are of the opinion that if you don't [insert some set of criteria here] that you shouldn't be diving, or at least diving certain dives. Not technical dives, but recreational dives. I don't think that you can do that, and that's exactly why you get so many posts criticizing people, but no one really being able to explain what you should do. It's just so much "come back when you know what you're doing", by which people simply mean, come back when you can do what
I think you should do.
And if the goal is to try and set a bar that says you must be this tall to ride this ride, then I don't think that's right. Not in recreational diving. Once certified, it should be up to the individual to decide their own risks within the limits of their training and their own judgment. Most people get that. Not 100%, but plenty.
I don't think there is any set of criteria that you can impose that says that you're
minimally competent to perform a dive. I suspect that most agencies think this too, which is exactly why the bar is set so low. It just doesn't take much to be a "minimally" competent diver.
There are many, many criteria that you can come up with that says that you are
more than minimally competent, and I think those are the responses that you have been getting.
This thread just seems a bit too much like, "what's wrong with dive certifications", just in a different wrapper.