Just FYI, in Greece
a boat with non EU flag is given a 6months permit
which can be either 6 consecutive months or a total of 6 months within a given 12months period.
Now, the good part is that if you have your boat in Kos island, you just sail 4.5 miles, right into Turkey, then you come back, preferably not on the same day ( ;-) ) and you get a new 6months permit! The sad thing is that you can do it only a number of times before getting into the eyes of the coast guard.
Want something better? If you get the ship out in the dry, (anywhere in Greece), say in late October and you deliver back the permit
, then 6 months later, in late April, you get a new 6mo permit for the summer season! This you can do for ever, it is perfectly legal
and in fact encouraged.
This is how many US ships spend years in Greek islands
, and I would not be surprised if the Croatians would devise a similar system in order to keep Non-EU sailing boats, provided of course that you don't opt for permanently moving your boat in Turkey, which makes things even easier.