The South Street Seaport musuem is a good place to go. It has been steadily shrinking, but it still has the lynchpin of its collection, the windjammer "Wavertree". At one point they had a fishing schooner the "Lettie G." too.
If you can get in, the NY Yacht Club is reputed to be an absolutely incredible place that puts just about every sailing museum to shame. I heard at one point that the clubhouse is available for events, so if you were to pretend to be interested in booking a function.....