I'm a big advocate of "establishing rapport" aka "sucking up." I've been known - not on a cruise - to spend time chatting with some of the higher ups. Ask about their families, what food do they like, blah, blah, blah. And do it regularly and not when they're busy of course. At/near the end tell them how much they've enjoyed getting to know them and where are they going next? Could you book that cruise? Just a thought.