Uninhabited island
From YPPedia
An uninhabited island (or uncolonized island) is an island that has not yet been taken under control by a flag. An uninhabited island cannot be set as home for any pirate, has no buildings placed (except those by Ocean Masters for operation of the game), and are often used for foraging commodities. They can also be used for porting vessels and launch points for Sea Monster Hunts and flotilla attacks.
List of islands
Below is a list of uninhabited islands. Islands not on this list have been colonized.