Amtrosie,
that's a good piece of information and advice - I'm not talking about the DMs or the instructors as they should do those types of checks themselves as a matter of pre-checks before the start of the day (at the very least). When you mention about OOA, unconscious divers and any other type of drills that are relevant - these should be the type of exercises that the DMs/Instructors should be doing on a regular basis and continually checking and updating their skills.
but considering where I live and the other people in the group when I go diving - they are people that come over here want to dive and see what the island has to offer in the way of aquatic life (do photog or whatever etc etc) and IMHO probably don't want to go through loads of safety checks before they do the dive (well, maybe my eyes are closed or naivety getting to me, as i've never seen anyone do any type of check apart from breathing through their second stage once they've set their gear up and doing BWRAF).
just my 2 cents