boulderjohn:When I signed up for my diving, I asked about Nitrox, and the person said that they normally didn't have any interest in it, but they could get it for me. It was clearly an issue for them.
They also told me that 35 minutes was standard for their dives. It did not matter what your computer said.
"normally didn't have any interest in it" is a far cry from cannot (or will not) get it for you. I think you ran into frank honesty. Normally, there was very little demand for nitrox among our client base. Nitrox was stored in that little building on the dock. No big deal to get a tank or two. Just need to know ahead of time if it's going to be a boatload as stock is limited to our supply on hand otherwise.
I take it you had a computer? Did your buddy? Was your buddy diving nitrox?
These issues are common difficulties for dive operations, all the more so if a diver signs up without a buddy. If a diver ends up buddied with a staff member on an afternoon dive, it is not unusual for that staff member to be doing his/her third dive of the day. Dive staff get bent too.