PerroneFord:I was directing this at everyone who has mentioned being a DM or diving with a DM. What I am asking is it common for a DM to essentially corral divers, keep an eye on their gas, and determine when to thumb a dive for a particular diver or group of divers.
Again, I have never been with a DM in the water, so I don't know if this is SOP.
Once they are in the water, they are then a GUIDE.