I don't know about Cancun salons, but I did manage a tanning salon for 4 years so I know a little about spray tans. How many days are you going to be in Cancun before your wedding? A spray tan normally lasts about 7-10 days depending on how dry your skin is (the drier your skin the longer it lasts). You also do NOT have to avoid the pool/ sand. You can swim with a spray tan. But obviously, it will fade faster than if you were not swimming. I recommend looking into somewhere that either uses a Norvell spray tan solution or has the Versaspa booth system. Those systems give you a more natural bronze glow instead of a orangeish glow that the Mystic tan can give. If you are only going to be in Cancun a couple of days before the wedding, I recommend doing it at home the day before you leave and making you "extra" dark so you still have great color when you get married. I hope this helps a bit!