When we came down in early May 2020, USVI already had a mask mandate and had limited restaurants to 50% capacity. The mask mandate was simple, no mask - no service (stores would actually refuse entry if you did not have a mask on). They had stopped all group gatherings and as of early June they had curfews on beaches (4 pm)
Sometime in early summer they suspended vacation rentals and stopped "bar" service - you could get a drink with dinner but that was it.
When we returned in October, you had to have a negative Covid Test within 5 days of arrival and file it through their online portal or quarantine for 14 days or until you got a test locally.
As of January, no negative test, no get on airplane. This was instituted after a group went to a wedding in Florida and brought back a "super spreader" event.
They are serious about it - if you serve a drink across a bar and are caught - they shut you down. I watched a couple refused service at an outdoor restaurant because they sat down without masks and indicated that they did not have them to wear.
But the good thing is the infection rate is probably lower than anywhere in the states. Plus they are administering all the vaccines they can get their hands on.