St. John has no commercial airport. For most trips, the real arrival route is STT airport → taxi → ferry terminal → Cruz Bay. Treat it as one connection with several moving parts.
Choose the ferry terminal with the whole day in mind
Red Hook normally offers the broadest schedule. Charlotte Amalie can reduce the road transfer when its ferry timing fits. The correct choice depends on the current published operator schedule, arrival time, luggage, weather, and how much connection margin you have.
Build in useful margin
Published arrival and departure times are not a protected airline connection. Bags, taxi loading, traffic, weather, and ticket lines can consume a tight plan. Keep medication, documents, a charger, and one change of essentials in your carry-on.
Verify on the day
Check your airline, the ferry operator, STT observation and island weather, and any official notices. A weather model can explain conditions; only the operator or relevant authority can confirm a cancellation.
St. John uses Atlantic Standard Time all year and does not observe daylight saving time.