An advanced OW cert card doesn't mean that much. Some folks go for AOW certification with virtually no diving experience, while others (like me) have been diving for many years (nearly 20 for me) with just an OW cert. Any Coz dive op worth its salt will dive with you a few times to see what kind of diver you really are before taking you to Punta Sur, Maracaibo, Barracuda, etc.... I am interested in trying out the "more challenging" dive sites and assumed that evidence of advanced diver would be asked for. Someone carrying a dive card with only 6 proven open water dives is not much proof.