Most of the time you get assigned a time slot to check in. The terminal is small and gets backed up when a lot of people show up at one time. Also most of the ships have off going passengers until 1130ish, if the ship came in on time. I don't know what time of year you are coming but that would make a difference with the fog issues. According to a buddy who works the terminal the doors are open for oncoming passengers at 11am, but if there are disembarking issues you will just get to stand in line and stare at the security folks.