The ferries are not running. Both Great Bay and Voyager have suspended service.

There are very limited exemptions to air travel, all of which require documentation and authorization. They've been posted for days in French, but this is the first time that I've seen them in English. Per The Daily Herald the exemptions are "an urgent personal or family reason; an urgent health reason; or a business reason that cannot be postponed" The same applies to flights between Guadeloupe, Martinique, and mainland France.
https://www.thedailyherald.sx/islan...-to-and-from-st-martin-and-st-barthelemy

There is a specially authorized boat run from St Barth to St Martin today, and only with a small group of passengers who meet the above requirements, in order for them to connect to flights. No passengers will be brought to St Barth.