The reference to St Thomas I can understand. This in the United States but outwith their customs area. Indeed one of its selling points is that the island is one big duty free experience. Consequently if leaving the island there you have the unique experience of passing customs on departure (but not arrival) but not immigration (either direction). The airlines then make a huge mountain-molehill and insist you turn up 3 hours plus before departure, then batch people through the customs experience clutching forms, nationality makes no difference, with all the commensurate queuing in tensa lines. Whereas in (e.g.) Puerto Rico you sail through the airport 45 minutes before the flight. It's a pretty offputting experience, I have to say, but the Virgin Islands are very beautiful, as are the Greek Islands, so it's just something that's part of the travel process. Moreover in both airports' cases the hassle is only on peak days. Comparing HER to STT is OTT (love those letters!), at HER turning up 75 minutes before departure is fine.