I agree but will go one step further.
Never ever entrust your safety of a buddy, DM or the management of the Dive Shop.
Take a Solo Diving Course and any other training which emphasizes "self sufficiency" as much as is humanly possible. I have seen many boat crews, DM's and other personnel who seem marginally competent. I have questions about the actual training received by these people.
Just as a DM will watch recently arrived divers for signs of competence by their ability to configure gear etc. nervousness, and other indicators, so do the same at your end with the Diving personnel themselves, the supposed experts.
It was in Belize a few years ago that I witnessed a near catastrophic incident which could have severely injured or killed several divers. The company was called "Belize Diving Services" and they were an incompetent and careless bunch. I think it is under new management thse days.
Just returned from Akumal on Mayan Riviera and saw several lapses of standard scuba procedures by supposedly VERY experienced DM's..
Same in Cozumel a few months before that.
This profession is really very loosely regulated if at all in many places. The certificate-granting theme-park called PADI is one reason among many for this.
Bottom line: Don't assume International or any standards. The visiting diver may "expect" it but will not usually (in fact rarely in my experience) get it.
Sy
I've now read all of this thread, as well as reports from the survivors. Nothing changes my view that in such waters the dive op should have had a positive way of tracking its DM, and hence the group. I stick to my view that the dive was severely mismanaged.
I haven't been to Indonesia or indeed anywhere in that region, but that's beside the point. There are international standards that should be applied to tourist operations seeking international customers (and indeed as someone said, probably run by ex-pats anyway). These are the standards that a visiting diver is entitled to expect. After all, the necessary equipment is neither expensive nor difficult to carry.