SXM and the nearby islands have each their own immigration rules for visitors.
We recommend you to check this in advance, since some countries have special visa requirements.
It is very easy to hop to other islands close to SXM with the plane. Every day there are flights for example to Saba, St Barths, Guadeloupe and Puerto Rico. The following airlines are our "local" providers for this adventure.
It is also very easy to take a ferry from Marigot, Simpson Bay or Philipsburg to the neigboring islands of Saba, St Barths and Anguilla.