My 14th dive was done in Molokini crater, following a PADI instructor (who was ostensibly teaching our "boat diving" class -- snort) and went to 130 feet, on a single Al80.
BUT -- we had warm water. We had 100 feet of viz. We had no current. All of my gear was mine, and as familiar to me as anything could be after only 14 dives. It was still stupid, from the gas management standpoint, but of course, nobody had taught me any gas management, and I DID get back on the boat with 500 psi.
If I had told someone ahead of time that we were going to do this dive (which, of course, I didn't know until we got there and the instructor briefed it) and that person had told me it was stupid, I would have argued with him, because, after all, an instructor was leading it. It would have taken some specific information, like an introduction to gas management principles, to have convinced me it was a bad idea.