My son is 15, almost 16 and fairly quiet and responsible. As I said, I trust him, just afraid of who else he might meet. He does not want to go on shore excursions, but be left to do "his own thing". Our one rule is that he get up and out of the cabin in the morning so that it can be cleaned for the day. Last cruise we'd return to the cabin at 1pm and he'd still be in bed! I told him he could go sleep in a deck chair the next day if he wants to stay out all night!