Travelling in the Dutch Caribbean
If you travel by ferry between St. Maarten, Saba, St. Eustatius and St. Kitts, a passport control will take place in some places. That's because sometimes you cross a national border, but sometimes you don't. Don't you cross a national border? Then there will be no passport control.
Caribbean Netherlands
The islands of Bonaire, St. Eustatius and Saba belong to the Caribbean Netherlands. There are no national borders within the Caribbean Netherlands, including between Saba and St. Eustatius. As a result, there are no border controls on these islands when you travel by ferry.
There will be a border control if you travel to the Caribbean Netherlands from a country outside this area or if you travel from the Caribbean Netherlands to a country outside this area.
In addition to border checks, checks may take place on the basis of immigration supervision or criminal proceedings. Please note that in this case you should be able to identify yourself.
Example
If you travel from Saba to St. Eustatius and then to St. Kitts, border control will only take place when you travel to St. Kitts and a passport will only be required at that time.