Just booked a 3 day cruise on the Sovereign but didn't get the late dinner seating. How can I get us moved from "waitlisted" for that seating? Would a tip to the Maitre D help? If so, how much?

That won't work. Call the line occasionally to see what has happened to the waitlist. When you get on board see the maitre'd right away. If there's no room, there's no room!

Just returned from 3 day cruise on NCL Majesty. Had similar experience. Even after talking with maitre'd onboard, still were stuck with first seating. Even our membership in Latitudes didn't impress him. So, we ate all three dinners in the alternative restaurant, the Bistro. Probably better than the main dining room! Don't know if the Sovereign has a similar restaurant, but it might be worth looking into. Have a great time, and enjoy the private island.

As soon as you board, go to the Pursers desk and request a change. Unfortunatley you can't do this prior to baording. They will usually accomodate you.

RCCL usually sets up a desk for dining room changes, it is usually in the foyer and is open during boarding up to the point of the 1st seating.