Check the ferry schedules. There's a link on the top of this page. Then, once you get your luggage go to the taxi dispatcher & either tell him you want to go to Red Hook or Charlotte Amalie, or, ask his opinion of which would be better, depending on time, traffic, etc. The total price(taxi &ferry) is nearly the same using either option. Red Hook is a longer taxi/shorter ferry ride; CA is shorter taxi/longer ferry.