Get there by 10:30 of 11:00am and you will beat the airport crowd and long lines. You should begin boarding no later than 12:30 . They will be serving lunch on the lido deck when you board. Eat first to avoid the lines, and then explore the ship. NO was the slowest port I ever sailed from so get there early.
What is the rush to board the cruise ship? You will be on the ship for days. I find that an hour before departure is fine. In November I am on an 11 day cruise to Mexico which departs at 8 PM. The earliest I will board is 6:30. By 6:30 there will be no lines and I will have the day in port. Besides, I will be on the ship for 11 days; I think I do with out the lunch on the day of departure.
We are doing cruise #12 and #13 this year and I'm with you Pebbs and FHall, the earlier the better. We like to be one of the first on. We drop off our carry-on in our cabin, eat lunch, then explore. Make supper club reservations, check out our dining room assignment and change if necessary. We even go to the main theater and check out the best seats so we know where to go at show time. I'm on vacation and want to enjoy every minute.