First of all I would check in at the closest custom's office to where you enter the waters. You want to make sure that you tell them it is a private boat so they don't charge you the charter prices. It might even be smart to have a notarized letter from the captain stating that you have permission to use his/her boat for pleasure and that is borrowed not chartered. It would probably be a whole lot easier if the captain just left it in the BVI for you to get to.