An account is given of the further spread of Elminius modestus along the German coast north of the Elbe towards the Danish coast. The population at Cuxhaven has spread to the outer estuary and Balanus balanoides is at several places in danger of extinction. Elminius modestus is now well established in several small harbours as well as on parts of the open coast between Cuxhaven and Dagbüller Hafen. The harbour populations have most probably been established by shipping but some marginal dispersion is taking place at suitable places. The species is absent north of Dagbüller Hafen: it has not yet reached Danish waters either by marginal dispersion or by a vector carrying it into any of the ports. Elminius modestus has not reached the north-eastern German coast.