We flew from EIS to STT and were required to submit the 3 day. Friends left earlier and took a water taxi and had to submit a 5 day. We are considering taking a water taxi vs the ferry in June (unless additional departures are offered). Water taxi websites indicate that a 5 day test is required to enter USVI via sea. This is consistent with private vessels entering USVI waters. I have friends in the USVI and they seem to feel that protocols will not be changing soon for vaccinated travelers.