Aquatic Rentals seems to get overlooked when people are considering ferries. They have an 8:30 RT departure that would give you plenty of time for a 1:50 flight. Last week I took their 9:00, which they’ve since changed to 8:30, and got to STT at 11:00. They go to Cruz Bay on St. John to clear in, then on to Red Hook. https://www.aquaticrentalsvi.com/ferry-service-tortola-bvi-stt-virginislands