The Taxi dispatcher is located just outside the airport  baggage claim area. Tell him the number in your group, and that you are headed to the Redhook ferry terminal to catch the ferry to St John. He will assign one of the waiting taxi van drivers to take care of your group, and you will be on your way as soon as your group has their luggage and are ready to go. The Redhook ferry departs to St John every hour on the hour.