pacificgal
Rest in Peace...
I learned stuff in that portion of my AOW class. You can't signal your buddy in the normal manner, making sure to signal your air, etc., in front of your light, don't shine your light in anyone's eyes, have a tank light, primary and back up, in case your primary fails. Orientation is hard to judge if you can't see the surface or the bottom. Check your pressure guage frequently, most SPG's are luminescent in you shine your light on it for a bit it will glow in the dark. Be careful for jellies, they tend to be drawn to flashlights (at least in Jamaica and Monterey they are). On my Jamaica night dive we had to jump off the boat without our flashlight on and descend to get under the layer of jellies before we could turn our light on. If you're uncomfortable making a descent in pitch black (or if you can't judge how fast you're descending without looking at your depth gauge), maybe you should hire that DM. I don't think it's a waste of money, if you find you're actually frightened of what you can't see past your dive light it may be comforting to know that you have an experienced there looking out for you.
Personally, I get a little freaked out by what could be just past the light of my beam.
Personally, I get a little freaked out by what could be just past the light of my beam.