The open water certificate consists of a series a dives starting with a confined water then a couple open water dives. You may as well get the two open water dives at an interesting sites. You can do them in New York but why bother?

It can be worth doing the confined water dives in a pool to save a day of your vacation and get an extra real dive in when you're there.

Take the course somewhere good where they really put you through the exercises including the emergency ascent.