Excellent question. The number one rule of diving nitrox is always analyze. However, I would bet if you were able to look down at all the rec. nitrox divers today an amazing number did not analyze.I'm taking my nitrox class next Wednesday. I was reading over the book in the class kit. It says that you should have your own analyzer and check the mix to verify the O2 percentage. How many of you rec divers actually check the mix yourself before you dive?
Why?
* Their brains are on vacation
* They are diving with a small boat that has their nitrox cylinders delivered and the boat does not have an analyzer on board. ( I just had one of our divers come in very frustrated about being in this situation, so he now has is own analyzer. )
* They are on a live-aboard and the crew is taking care of it or they see the analyzer the membrane is using and go by it.
Personally, I always analyze.