Gemma,
Nice to see you found this board. You have a number of options:
1) If you want to stay in the pool most of the Masters teams in the city have a visitor's policy that will allow drop- ins, it helps if you are in a masters team, and a USMS member; some of the NY teams are: Bearcats (swim at Baruch College), TNYA- several pools, Red Tide, Aqua Masters, and a few more
2) If you can handle 55F water and want to swim at Coney Island there are some crazy people who are already out there now swimming, you can arrange to meet there with the CIBBOWS group on weekend mornings, weekdays is harder
Hope that helps, happy swimming.
Andreas.