You need to use Roadtown Fast Ferry at 10 AM Gets you to STT around 11. You should be at the airport by 11:45AM Download your boarding pass. There is a deadline (non-negotiable) of 2 hours before the flight. After that 2 hour limit, they CANNOT accept your baggage. So you must be at the airline desk (Not just waiting in line) by 12:35. Sat may be a problem as it can get very busy.