Sag Harbor-NYC-Atlantic City
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Your first day will be the toughest, onsidering you will have to go around Orient Point. Once you round the point, your only harbors are Mattituck, then Mount Sinai and Port Jefferson. They are not that close. Depending on when you leave Sag Harbor, you may want to stop in Greenport your first night, then start early the next day for Port Jeff. Once you reach Port Jeff, there are many places to stop.