As Martinique is a Departement Outre Mer of
France and consider a part of metropolitan
France there is no importation if you sail from France to Martinique. Technically it is a domestic sail in the same way the flight from Paris to Martinique is a domestic flight.
So if you are an EU flagged
boat sailing from the EU to Martinique you are technically doing an EU
passage. As long as you have all your paperwork in place there will be no issues when you arrive. This also applies for Guadaloupe, also a DOM.
However once you leave Martinique you will still be subject to all the usual
customs regulations you find outwith the EU