Hi again mohrl,
Unfortunately we did not leave from N.Y. because it was several weeks after 9-11.
We had to go by bus to Boston, but it was a wonderful busride through indian summer coloured landscapes. So, I´m not familiar with the port in N.Y., but its close to the centrum.
In Boston you can make a long walk by your own.
Take the bus shuttle to the centrum, follow a special way, which is marked on the street (red line ??? I`m not sure) and it brings you to very nice places in Boston.
Bar Harbour: also a nice walking tour along the coast line and then in s small centrum.
If its whale watching season, take a boat tour.
In Halifax make a bus tour to Peggys Cove, one of the most fotographed places in the world and very nice.
But enjoy the cruise, stay outside as often as you can. In september/october you can see whales and doplphins.
It is really wonderful.
Best wishes for your cruise,