It seems the thread has turned into, "get a padi aow card - because there might be, maybe, sometime, somewhere in your future, the possibility of maybe running into an operation that only takes that card." Someone mentioned earlier that their thought was that r3 was only about selling courses - well what is this? This is fear tactics selling at their best!
Honestly - how often does one go on a dive vacation with no plan, randomly picks a new dive op with no contact, and shows up with no reservation just before the boat leaves - only to discover the boat has room for one more, but you can't go - because you forgot your padi aow card and no other card will work? This scenario is few and far between!
First of all, show me a dive op that only accepts padi, and I'll show you one that accepts visa right next door!
Second, while such an exclusive dive op might somewhere exist, one might ask themselves, "Is that the operation I want to dive with?" Because chances are, their target market is likely the cattle boat type.
Third, one way to mitigate the fear of not carrying a padi card is to look for operators with other agency affiliations.
Fourth, by making contact and a reservation in advance, you not only secure a guaranteed spot on a boat that is actually going out, but get all the equivalent card issues sorted in advance.
Take fundies / essentials now, and if by chance you do actually find a padi only operation that you absolutely have to dive with, take that as an opportunity to hire them for your aow guided dives. That way you get the boat, five guided dives, and a souvenir card all together in one nifty package deal! And if you never run into such an op, then you are ahead of the game because you never had to buy that card.
Every once in a while someone mentions the nebulous padi only op, so please post some verifiable references to such operations, and let's review them and their competitors.
Cheers