Getting to the Festival
Governors Island is accessible by three ferries, one leaving from Manhattan ($2 roundtrip), one leaving from Brooklyn ($2 roundtrip), and one that makes several stops along the East River ($2.75 each way).
The Manhattan and Brooklyn ferries are both operated by Governors Island, and you can find the complete, up-to-date ferry schedules for each route on their website.
The Manhattan Ferry departs from the Battery Maritime Building at 10 South Street, New York, NY. The Ferry landing is immediately east of the Staten Island Ferry (but not the same building). It is at the very southern tip of Manhattan and easily accessible from the 1,4,5,N,R,J or Z trains.
The Brooklyn Ferry disembarks from Pier 6 in Brooklyn Bridge Park, located at the foot of Atlantic Avenue (corner of Columbia Street). It is accessible via the R,2,3,4,5 trains and the B23, B65, B61 buses.
The East River Ferry is operated by NYC Ferry. A complete, up-to-date ferry schedule listing the locations of all stops is available on their website.
Here is a link to a downloadable PDF map of Governors Island that shows you the walking routes from each of the ferry landings on the island to Colonel's Row.