Although you can move freely between countries in the EU (provided you are an EU citizen or come from a country that has automatice schengen visas or have an approved schengen visa) that is not quite the case for all EU countries when it come to boats, In Greece
for example, you must report to custome and port police for passport checks and boat documentation
. You will receive a log book in which you should document your journey by visiting the port police at each port. This actually does not work as thoroughly as that and is currently in a significant state of flux. Each country you visit has its own policies and procedures. When you move out of the EU, the rules change again, but generally speaking , you will need to present yourselves, your crew and your boat for visitor control, documentation
and the commencement of a prcess to record
your progress around the country's waters. This requirement is also to collect fees
. noonsite gives you some ideas, pilot guides help and some countries have websites that explain it all. Why all this rigmarole? Security
. Boats are often used to smuggle people and products into countries. Because of international agreements, countries are obliged to care for you in the event of a boating
catastrophe and they like to know that you are in the country and the details of the boat that you are travelling in. They also want some compensation for all of the services they provide to boaters.