A new commercial ferry dock at the foot of Atlantic Avenue will let Brooklynites get to Governors Island faster than Manhattanites - in three minutes, versus seven. Constructed with a $1 million grant from The Port Authority of New York and New Jersey and $400,000 from city Councilman Bill de Blasio of Brooklyn, the dock will open next summer at the Brooklyn Bridge Park for ferry service to and from Governors Island, and eventually to other harbor landings.