I usually dive solo - when I see an instructor with a class in the cave I try to stay out of the way and not interfere with the drills - it's complicated enough on the students without having somebody come plowing through the middle of it, lights on behind a scooter, etc. If it's a lights out drill I cover my light. If they are on the line I get away as much as I can. And God forbid if they need help, I'll assist in any way possible - but otherwise I stay away.

Mark