Hi, I am planning on a Disney cruise soon. I am going with my 19 and 20 year old kids. I know they will be able to drink in Nassau. I really don't have a problem with them drinking a little on the ship, as they know when to stop and are responsible about it all. I would like to know: -Are their id cards marked (either physically or in the computer) that they are not 21, so there's no chance they will be served alcohol? -Will they be served if they "look" old/mature? Thanks.