To whom do small islands belong? What role do they play in the processes of colonization and maritime territorialization? In what way does the exploitation of their resources contribute to making them central to power and sovereignty conflicts? This article considers the colonization of the Maghreb from the perspective of island spaces as ‘land-sea regimes’. It focuses on an archipelago located off the coast of Tabarka, on the maritime border of Algeria and Tunisia. Frequented for centuries by fishermen exploiting the coral in the region, the Galite became a geostrategic place in the 19th century for coastal security, maritime trade and fishing. The study of the fishermen’s families who settled there from the 1870s onwards, their networks and their relations with the authorities, invites us to reconsider the history of the colonization of North Africa from the sea and the islands.