My nitrox course was a the PADI course before they dropped the dive requirements. It was actually a good course and went beyond the little booklet they use with it. I rarely dive nitrox now. If I'm doing anything other than air it's got helium in the mix. Cost is not a factor. My air, and nitrox if I choose to use it, are shop perks. I used to use it for checkouts with large classes where we had to split up the groups. Those days I'd do 6,8, even 10 dives in a day. Short, shallow, but they add up.
Nitrox paid off there because when you are diving that much and BECAUSE PEOPLE ARE DIFFERENT saying the air tables are so safe you don't need the added safety factor is big bull caca. Anyone can get bent. If you even read the tables there's a little disclaimer that says something like "these are not guaranteed to keep you safe".
The risk of DCS is so low on air tables that the extra margin is a waste of money? By whose definition is that statement made? Any diver who chooses to add an extra margin of safety to his/her profile is in no way wasting money. By this standard using a 5 mil instead of a 3 because a person gets cold easily is a waste of money, right? And what factors do you take into consideration concerning a particular diver to say to him/her you are wasting money. Age, sex, weight, existing medical conditions, do you have access to their bank account as well so you can do a financial analysis of their diving habits. Go read some DAN accident reports before you make a blanket statement like that. For many people, I will not even say most, the tables are safe. But what about the guy who may be a little dehydrated and not realize it who using the air tables pushes them a little. Still within NDL's but the dehydration, physical condtion, water temps, etc may put him into the area where the air tables are not safe enough. For a DM to make that kind of statement to a newdiver is distressing to say the least.
I do not teach nitrox as the YMCA no longer offers it. I refer people to the NAUI instructor at our shop who requires students to analyze, observe the blending process, and dive with the gas. Just how does the SDA teach you to use an analyzer and which one? When do you analyze your gas? What happens if it's not where it should be? Do you get a new fill or adjust to the new percentage? Whose tables do you use for calculating your NDL's and what algorithm are they based on?
Personally I use my comp when diving nitrox which is based on DSAT tables(PADI). Therefore I use my PADI tables as backup. It's been well over a year since I used it though. Just has not been necessary as since getting some technical training I don't mind going into a little deco. For this I use V-Planner. If Ithink I'm going to be pushing my NDL's at all even on air I'll generate a deco schedule and keep it in my wetnotes and on the wrist slate. Diving air tables is not safe. It is SAFER than diving with nothing but it is no guarantee of avoiding DCS. And then whose air tables? PADI's, NAUI's, YMCA's, or how about the Navy tables that are based on years of research and experience with young fit men? This middle aged guy with w/little extra weight and who used to smoke and has a little tough of arthritis in my hands does not feel comfy pushing the Navy tables. If I thought I'd be doing that and not want to do deco for whatever reason I'd use Nitrox.
One other question. Is the SDA approved by VirtualDiveCenter.net.com.poopoo and are they paying them their on line royalties. If not they in trouble!