I didnt say he was a nanny. Are you implying that a DM has no professional obligation to the divers on his boat? If so, why is he required to carry insurance?
Because like any diver he might get sued. Just like ANY dive buddy might be. Its why insurance policies cover liability even for non "professionals". His professional role involves providing a brief and logistic support. The DM doesn't even have to dive. He also assists instructors with non-certified divers so needs liability there.
What Divemaster do you know that lets someone splash without a mask on?
And what if the DM is already in the water with another pair of divers? Or tying the boat off? Or briefing another pair away from the swim deck. A DM isn't there to catch the terminally stupid. If you're dull enough to jump in without a mask (i) its your fault and (ii) its not exactly life threatening. Learn from that mistake or give up diving.
Not ensuring the divers air is on is about as negligent as letting a diver jump in with a reg in his mouth that isnt attached to his tank....Have you ever heard of the term Global awareness?
Not the case at all. If you're dealing with an unqualified student who is RELYING on you for safety as they aren't trained to know better then yes. But you're dealing with certified divers all of which have been trained, signed forms and have qualifications stating (i) they're not that incompetent and (ii) if they are its their own fault.
Nowhere in ANY of the instructor manuals, roles or other materials does it state "A divemaster is a nanny to look after divers who although claim to be qualified dont meet the definition". A DM is primarily logistics when dealing with certified divers. He's not qualified nor should be be a babysitter for divers that allegedly dont need it.
So in your opinion, if someone else sets your gear up for you, that excuses you from needing to check it yourself, despite the fact that's what you were trained to do and you just signed a waiver saying you would do. Got it
Its like "Heres some nitrox, the guy at the shop blended it, theres no need to analyse it. Just go dive". Thats no different to letting someone built the gear for you, dress you and just rolling in without checking.
Why are people always so keen to pass blame onto someone else even when its their own idiotic mistake. Everyone makes mistakes - however the good people admit to them and learn from them instead of looking to blame someone else for it.