A Ferry that runs back and forth after 4:30pm that takes 3 hours. Where does this info come from. Be careful if planning around this as I am not sure it exists.
The only options I know of for Intl. flights arriving that late are to stay in the City and Water Taxi in the morning, or fly that evening on either Tropic or Maya. Also, contrary to all the info above, we have had guests miss the last Water Taxi after a prompt 2:35pm arrival at Intl. An hour is a reasonable time to clear the airport - from landing to getting in the taxi - and the drive can account for half an hour to the Swing Bridge, which leaves a 30 minute window for error - not much if you consider things like Intl. flight delays, late baggage, customs queue, no taxi, heavy traffic.