Don't give up, once on the ship. We booked our last cruise 3 days before sailing. We didn't even get documents or luggage tags before the sailing. Last group allowed to board. There was NO way, they said, I could get late seating. That was not do-able with my kids (ages 5 and 3 at the time). The second day we went to the first seating and spoke with the guy in charge, and there was openings as people just don't show up for their assigned dinner (they eat buffet, they eat on the island, they eat room service, etc.) Anyhow, he knew of a family or two that were not planning to eat at all, and we got their seats the next 5 days.