The New York City Downtown Boathouse offers free kayaking trips on the Hudson River. The Boathouse is an all-volunteer organization that is dedicated to providing access to the Hudson River for everyone. The Boathouse is located in the Hudson River Park, and has a permit from the Hudson River Park Trust to operate in the park. Walk up and take their kayaks out for an easy 20-minute paddle. After you practice a few times, you can go on a three-hour guided tour. There are often long lines so check out their website before you go.