Just got off the Dawn on Dec 30 from NY. I dont' have any help on getting there other then get there early and be prepared to stand in line.
The whole NY experience for us was the worst in my life. It is not set up for a cruise ship. To get from where you are dropped off to the where you can get on the boat you have to take an elevator. Imagine hundreds of people arriving and trying to get into this elevator. Then when you get out of the elevator we had to stand in line for something like 3 hours while we filed like cattle to find 2 people checking tickets, then you have to go through security, then you have to go through the boats boarding procedure. After the 3+ hours of standing in line, they have the nerve to have someone standing there to take you picture and asks you to smile.
Getting off the boats was just as bad. Being a non american, we had to, again like cattle, file into the theater where we proceeded to wait for 2 hours because they said they had to call imigration to come to the boat, they didn't have anyone waiting.
Worse experience of my life, my recommendation to NCL is to drop the NY route ASAP. I believe that they lost about 1000 future cruisers (thats how many were in the theater).