Iztok asked a very good series of questions IMHO (I know they were very good because I've been thinking them!). So I went to the PADI Instructor Manual (circa 2009) to see if there WAS any decent definitions/guidelines for what appears to be the norm for Island guided dives. Here is what I found:
Do not conduct open water training dives or Discover Scuba Diving experience dives in caves, caverns, under ice or in any situation where direct vertical access to the surface is not possible. Exceptions include Ice, Cavern or Wreck Diver Specialty courses, and special orientation dives for certified divers.
[Note -- for those who are NOT PADI instructors, the relevance of the "blue" color is that the language is a "standard" while the black color is a "suggestion or comment" and is not found in the "new" Instructor manual.]
So is it OK within PADI standards to be doing what the Island Dive Industry is doing? Well, perhaps these are "special orientation dives for certified divers" and thus OK -- but perhaps they are not. I've been in the Cathedral off of Lanai and it is, in fact, a very benign "overhead" (actually, I didn't, and don't, even consider it an overhead). I've also done swimthroughs of any number of wrecks (Rhone for example) which are also quite benign.
I don't see doing those as a problem -- EXCEPT for the following issues:
a. Giving people a false sense of "It is OK" to go into an overhead (whether it be rock, steel, ice or virtual) because "Hey, I did it in the Islands."
b. Giving people the mixed message of "Do as I say, not as I do" which is NEVER a good thing for an instructor. "Hey, if it really is OK to ignore what I was taught and go into this overhead, then what else was BS and I can blow off?"
I know the Island Dive Industry likes to do these dives because they ARE fun and give the customer a "good experience" which is good for business. I wish the Island Dive Industry did a better job of explaining WHY it was OK to blow off the training recommendations for "X" dive in this particular instance so that the "average vacation diver" wouldn't get the idea that it was, in fact, OK to do this type of diving without further, and appropriate training.
A little personal information about my experience with the Island Dive Industry -- dive number 17, Molokini, 141 feet. On getting back to the boat, I was asked how deep I went -- answer 141 feet -- the response - High Fives from the DM for having the deepest dive!