Pier 17 on South Seaport Street is a great spot to hang out!
Besides the great view to relax in a beautiful weather by the water & Brooklyn Bridge, you can also find fun activities to enjoy your weekend in NYC!check out Water Taxi, get on the ride along Hudson River to enjoy Manhattan view.
or if you want to get experience of bigger boat ride, try "Clipper City, NYC'S largest Tall ship", they'll take you on the massive sailing and give you the tour of New York City's Harbor.
the Daytime Sails is 90 minutes at 2:15pm-4:30pm/ticket is $39(adult) w/ free drink at the bar on the ship. and Twilight Sails is 2 hours at 7pm/ ticket is $45(adult) w/ free drink.
Water Taxi Beach Tent with the fun activities you can enjoy!!
Food vendors, variety of dishes you can pick!
or drinking in the sunny day by breezy pier under Brooklyn bridge
mini Golf that you can have some fun, only $7 per person!
After finishing up with Downtown area, if you want to head up to Uptown in upper east side area, you can always stop by at the Metropolitan Museum, and go up the the special Roof Top exhibit to view big bamboo installation and to get some fresh air of NYC and view a great sight of Manhattan and Central Park!
"BIG BAMBU" by Doug & Mike Starn on the Roof (at the MET)