Szczecin Lagoon

Szczecin Lagoon, Stettin Lagoon, Bay of Szczecin, or Stettin Bay , also Oder 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 in the West and the Wielki Zalew in the East. An ambiguous historical German name was Frisches Haff, which later exclusively referred to the Vistula Lagoon.
From the South, the lagoon is fed by several arms of the Oder river and smaller rivers like Ziese, Peene, Zarow, Uecker, and Ina. In the North, the lagoon is connected to the Baltic Sea's Bay of Pomerania with the three straits Peenestrom, Świna and Dziwna, which divide the mainland and the islands of Usedom and Wolin.

Wikipedia