The Downtown Boathouse offers free kayaking in the Hudson River every weekend from mid-May to mid-October, and during July and August, they offer extended weekday hours in the evening. Boaters get to paddle around in the water off of Pier 26, and while there is a 20-minute time limit, kayakers often stay out longer if no one is waiting. The boathouse provides lockers, changing rooms, sunscreen, and bike locks.

Brooklyn Bridge Park added free kayaking to its roster of fun things when Pier 2 opened last year. Like the kayaking at Pier 26, it's completely free, and there is a 20-minute time limit. Unlike Pier 26, it seems that the park is strict on this limit, as there is usually a line of anxious paddlers awaiting their turns. Boaters get to splash about in the East River between Piers 1 and 2 on Saturdays and Thursday evenings through the end of August.

Situated on Jamaica Bay, Floyd Bennet Field feels like a world away from Manhattan. It's part of the Gateway National Recreation Area, and the National Parks of New York Harbor Conservancy host frequent kayaking excursions in the summer. Most of the remaining tours take place on weekday mornings. You can find the full schedule, and details on how to RSVP here.

The Manhattan Community Boathouse also offers free kayaking on Pier i near 72nd Street every Saturday and Sunday until September 5 from 10 a.m. to 5 p.m.

The Long Island City Boathouse doesn't stop the fun once Labor Day passes; this aquatic crew keeps paddling through mid-September (judging by their calendar, it also looks like they'll be participating in Open House New York in October). The LIC Boathouse offers a solid selection of trips for experienced kayakers, including escorting Urban Swim participants through the East River and an annual circumnavigation of Manhattan (it fills up fast, so if paddling in the Harbor under the moonlight sounds like your idea of fun, be sure to sign up in advance).

Since launching in 2010, the NBBC has been getting wannabe sailors on the water around Williamsburg and Greenpoint—even the intensely polluted Newtown Creek. Outings are offered for different skill levels and on different vessels (canoes or kayaks), and are often paired with another activity, like a boat trip to Red Hook that also includes a pit-stop for brunch.

This volunteer-run boat club launches from Staten Island's South Beach, and offers 15-minute windows in which newbie sailors can paddle around the waters off the beach. Sessions begin at noon, but act fast: The last one of the season happens on Saturday, August 29.

Don't let the name Manhattan Kayak fool you: the group that runs the water activities at Pier 84 offers more than just standard kayaking. They host paddle board lessons for beginners ($35); hour-long SUP yoga classes ($40); skyline kayak tours ($60); surf-ski, "the fastest one-person paddle craft in the world," lessons ($95); a 4-5 hour tour up and back to the GW Bridge ($125); and so much more. And they keep paddling until the end of October, so the end of summer does not mean the end of water sports.

As its name implies Rockaway Jet Ski offers jet ski rentals and tours, but they also rent kayaks (1-hour rental costs $30 for a two-seater) and SUPs ($35 an hour for a standard rental) for those who want a more low-key watercraft. Jet ski rentals cost $140 for an hour, or you can take a 4-hour tour around the harbor for $350.

Sea the City helpfully maps out each of the three tours that it offers, so you can see exactly where you'll be zooming. For $379 (+ $59 for a second rider), you can circumnavigate Manhattan on a three-hour trip or for $329 (+ $49), you can ride past the Statue of Liberty in addition to seeing parts of the Hudson and East Rivers. The cheapest option is a $159 (+ $39) for an hour-long jaunt around the harbor. Discounts apply if you book multiple jet skis, and they also have happy hour tours Monday to Thursday.

Most jet ski tours stick to the man sites in Manhattan, but Jetty Jumpers also offers tour around Coney Island and the Verrazano-Narrows Bridge, as well two sunset tours and three sunrise tours. They operate through mid-October.

Skip the hipster-filled beaches of Rockaway and head east on the peninsula to the much-less-crowded surfing beaches, where you can learn to ride the waves. Skudin Surf has a variety of lesson types, ranging from $65 weekend group lessons to $85 yoga and surf sessions to week-long surf camps for $435. Private and semi-private lessons are also available.

After 20 years of operating out of the North Cove Marina in Battery Park City, Manhattan Sail was forced to relocate all of its business to its Jersey City location. They offer two introductory courses, plus a handful of lessons for experienced sailers, like how to navigate the coast and waters and "bareboat chartering," which evidently gives you the ability to "rent a beautiful boat and take it sailing with friends or family."