I worked in the Harborside Financial Center adjacent to the Hyatt for almost 10 years, commuting every work day via the PATH. The NY Waterway ferry was the backup in case PATH wasn’t running; that happened at least once a year. The ferry between Brookfield (WTC) and the ferry landing at Paulus Hook operates pretty consistently; the major issues are during the winter when ice in the Hudson River can force a route down towards Ellis Island, adding quite a bit of travel time.

Many visitors are probably unaware that there’s a free bus service that can be used in conjunction with a ferry ticket. Here’s the weekend service page: https://www.nywaterway.com/weekends.aspx