While in NYC you might try picking up a mooring at Pier 40 by Houston St. just north of the Holland Tunnel air shaft on the Manhattan side. They have about 16 moorings and a few are empty. They are operated by NYC Parks and the normal fee is around $40/night. Almost no services or amenities and you need a dink to get to shore. The last folks I steered to this place did not even have to pay (a few weeks ago) as the staff seem to think that the season is 'over'. Pretty sure Nyack Boat Club is around $25/night for a guest mooring - nice club and town. Nyack is only about 10 miles down river from Haverstraw though. Have fun.