We were on the Mariner in Alaska last June and will be on the Navigator out of San Juan in March. While the reservations only restaurants take only one set of reservations,they will sometimes accomodate walk-ins later in the evening. They stagger the reservations so as not to get too frantic and are prepared to reset the earliest tables for latecomers if possible. Check with the maitre d' later in the meal but early enough to go to Compass Rose if you can't get in.
