This Adv. Nitrox course is, from my understanding, a kind of precursor to full technical diving. I will be talking to the instructor tonight. I will find out exactly what is involved. From the course description I read that it can be done with a recreational configuration at this point (although I may be mistaken & will get every detail I can when I talk to the instructor) with the addition of a large pony bottle or deco bottle (O2 cleaned of course).
You are correct - course standards (at least for the IANTD course) state that the only special gear required is a deco bottle. I usually encourage people to take the course with a redundant regulator, though (single with a Y or H valve, or manifolded doubles). My personal opinion is that any time you are in an overhead environment (whether it is physical or "glass"), then you are
much better off with redundancy in your primary gas supply, since surfacing immediately is no longer a valid bailout option for resolving a problem.
One other thing to consider is whether you can meet the bottom time requirements using only a single cylinder. The IANTD course requires a total of 120 minutes of BT in 4 dives, and then of course any deco dives must be planned using the thirds rule. I don't know what your gas consumption is like, but I'd venture to say that many folks would find a 30 minute dive to 100+ feet to be a bit of challenge with just a single cylinder. Doubles OTOH, should give you plenty of gas.
Plus just having knowledge & experience with & of decompression procedures can help me in a pinch if I decide to stay as a recreational diver & ever get myself into a pinch where that would be necessary.
If you're interested in learning more about decompression procedures, then you might consider taking a YMCA Silver Advanced or NAUI Master Diver course. This is a "rec" level course where they normally cover things like decompression theory, gas management, deco procedures, etc. If you take the course from someone who does a lot of tech diving, then you'll get the tech "flavor" on the decompression side of things, along with an opportunity to do a simulated decompression dive (i.e. a dive that is actually within the NDL, but where you carry out a decompression profile as if it had been a deco dive). That will give you a "taste" of tech diving, but still within the realm of recreational training.
Either one of these courses will also teach you instructor-level knowledge of a lot of different topics, which will help prepare you for the DM course. It's something to think about, anyway.
