I guess I started the detour by mentioning the nitrox fill issue at the park but, WOW, you all have sure run with it! I must point out since the issue of training has been brought up, how much information is enough in a basic enriched air diver course to 40%? a majority of issues discussed here would be more apropriate in an advanced nitrox course and especially in a gas blender course. This thread has now overwhelmed and scared Scuba Jerm away from a nitrox course. Should I bash the SCUBA industry and my agencies standards to my students in an effort to give them all the facts? Or should I teach them the standards and then focous on actually diving nitrox safley eg. EAD & MOD formulas, expanded table use, anylizer use ect. at what point do we overwhelm our students? If trianing is limited on the fill issue in the basic course well, shouldn't it be to a point? I surley dont have my open water students run through the Encyclopeadia of Recreational Diving and give them exams on Phyisics, physiology, Dive Theroy, and Equiptment. While that information may be relevent and make them better divers overall it is outside the scope of the course and would absolutly overwhelm them. The real point is saftey first, FUN second. Yes the bands are marketing, yes the standards are conservitive. If you wish to have standards changed you are arguing to the wrong people, shops and instructors don't make the standards but are legally required to abide by them! Start a pettition to fund real research get real data to back up your point of view and present it to the powers that be, the ones that write the standards, not those that are forced to abide by them. Just a thought.