I could never understand why anyone could have difficulty comprehending how easy it is to get lost in a hard overhead environment and run out of breathing gas. Nothing deceptive about it and no special training is required. Does diver training discourage thinking and depend solely on memorizing rules?
I don't think it's about diver training discouraging thinking... it just seems that it is not as self-evident to some divers as one would hope.
A couple of months ago I was in Sharm Al Sheikh, Egypt diving some wrecks and caves. One particular cave we dove was located inside a very popular OW reef that is frequented by a large amount of divers daily. The cave opening itself is only at 6m and has a beautiful entrance with sunlight penetrating further into areas of the cave due to openings from the top of the reef... openings far too small for any divers to swim through as an exit. Nevertheless, it does lead some divers unaware of the structure of the cave to mistakingly swim inside thinking that an exit is just a little further down the cave where the light is. Unfortunately, by the time they discover this is not an actual exit they have elarady silted up the envinrment and have lost the way out.
I was told after completing the dive (with the proper equpenmt and guidelines etc..) that only a coupe of months prior to my arrival two OW divers went into the shallow cave... they got lost. One managed to find his way out, the other was later
recovered at about 40 meters inside the cave and only 3m from the surface.
This has happened more often than dive operators here care to remember and if you are also familiar with other wrecks in the Red Sea and the Blue Hole and Canyon sites in Dahab, far too many divers at various experience levels have perished. There are memorial plaques on the rocks there as a somber reminder. These are not some out of the way esoteric dive sites... these are very popular high density areas that are visited by thousands of divers every year - and without assigning blame to the operators, the guides, or even the diver themselves... it has happened far too often over here, and will probably continue to happen.
I wish that the dangers were indeed self-evident, but unfortunately they are not to an unacceptable amount of dead divers.