What I do on the deep dive is the following:
1. Plan the dive with adequate gas supply using the student's SAC rate that they determined on an earlier dive
2. Choose the appropriate tank for the dive. Ie an Al80 is not acceptable for a 100 ft dive. Students use 100 cu ft or larger HP tanks or an LP tank like a 95 pumped to 3000 PSI giving them a 108. or doubles if they want to.
3. Select the stage bottle. Either a 30 or 40 cu ft depending on what they have or can rent.
4. After entering the water we descend to approx 50 ft and hang the stage bottles on the descent line or if vis is bad they carry them.
5. Descend to 95- 100 ft depending on the site and I will give them a couple quick hand signals to see if they are impaired and judge reaction. Then we tie off a reel and they run it out approximately 100 ft. Stop, turn, and take up the line while managing their light as it's dark where we are as well as cold, and keeping track of their buddy.
6. Reach the tie off and they undo the tie off, secure the reel and hand it to me.
7. Then we make for the ascent line. Somewhere between the hand off and starting up the line I pull an Out Of Air on them. If they are narced I'll know when they just look at me numbly or get wide eyed ( if this happens I grab em).
8. Share air horizontal and in trim up the line to 50 ft where we then deploy the stage bottles. One at a time using proper gas switching procedures.
9. Finish the dive using deep stops and simulated deco to end the dive as a multi level dive.
10. Doing it this way has them in the water for a total run time of about 45 minutes for the deep dive as opposed to the 20 minute down and up most do.
I prefer to use actual dive skills to demonstrate narcosis as opposed to kids games that for some people show nothing and give them the idea that they were not narced. The tests I use show them as there is always some level of impairment on one or more of the skills.
I've had people who did not remember handing the reel off to me. And be fine on just about everything else. I began to do this when I saw people get faster on locks, tic tac toe, etc. at depth than they were on the surface. And it made them cocky. Not gonna happen in my class.
Oh, normally there are no more than 2 students per Advanced class. I will take a third if they are judged to be exceptional divers in the first place. But that is very rare. I'd rather do two and then the third as a private class as my advanced level classes are pretty intense. And you can fail them. They are not tours or tastes of advanced dives. There are new skills on every dive such that if you don't have your basics down good it's better if you don't take this class as you will just get frustrated.
If there's any question we'll do some evaluation dives at no cost to you, other than the gear you need to rent, to be sure I'll even allow you into the class or require some remediation in the form of workshops or just get some dives in on your own to work on the skills you should have gotten in OW.
Ie basic skills, buoyancy, trim, planning and executing dives without a DM or instructor overseeing you. That kind of stuff.