If you've not been to St John then I suggest a CYOA charter from St Thomas. Visit the north shore of St John (day 1), then day 2 on the south shore, day 3 make the 5 hr sail to Christiansted, St Croix. Day 4 head to Buck Island
, St Croix. Day 5 return to St John, Day 6 downwind to St Thomas anchorage (e.g. Magens Bay, Christmas Cove, or Apostle Island), Day 7 back to base. Or on day 5 sail doenwind to Culebra, day 6 at Culebrita, day 7 back to St Thomas.