Szczecin Lagoon (, , since 1945 sometimes also Oderhaff (Oder lagoon) or Pommersches Haff (Pomeranian lagoon)) is a lagoon in the Oder estuary, shared by Germany and Poland. It is separated from the Pomeranian Bay of the Baltic Sea by the islands of Usedom and Wolin. The lagoon is subdivided into the Kleines Haff (, "small lagoon") in the West and the Wielki Zalew (, "great lagoon") in the East. An ambiguous historical German name was Frisches Haff, which later exclusively referred to the Vistula Lagoon.Erhard Riemann, Alfred Schoenfeldt, Ulrich Tolksdorf, Reinhard Goltz, Akademie der Wissenschaften und der Literatur (Germany), Akademie der Wissenschaften und der Literatur, Mainz, Preussisches Wörterbuch: Deutsche Mundarten Ost- und Westpreussens, 6th edition, Wachholtz, 1974, p.595,
