Sounds like enough time.
You will have to clear C&I coming in from VG -- if that is the same C&I you may be able to go directly to the departure area. If you clear C&I at a separate location you will have to pass through again at the main airport entrance before clearing TSA.
For sure have your boarding passes printed and in hand before this all.!!!
Similar to landing by ferry - you must clear into the USA and again later out of the STT point of departure.

Last edited by LocalSailor; 11/09/2018 02:45 PM.