It was a cool end-of-summer day when I went over Labor Day weekend to do some kayaking out on the Hudson, but it was windy and the waves carried me around the water, giving my arms more of a work-out every time the kayak went out of bounds!
There is also free kayaking out in Astoria off of Socrates Sculpture Park: www.licboathouse.org.
View toward Jersey City and Hoboken
The Goldman Sachs Tower in Jersey City plus surrounding businesses
View towards Lower Manhattan