Riverine Flotilla of the Polish Navy

The Riverine Flotilla of the Polish Navy (Polish: Flotylla Rzeczna Marynarki Wojennej), better known as the Pinsk Flotilla, was the inland branch of the Polish Navy operating on the Vistula river and in the area of the Pinsk Marshes (Dnieper–Bug Canal) between the Polish-Bolshevik War and World War II. Under Commodore Witold Zajączkowski, it was active in the invasion of Poland and fought against both German and Soviet forces.

During the Polish-Bolshevik War the Pinsk Marshes proved to be almost impassable to troops of both sides. Lack of roads and railways posed a serious danger to infantry and cavalry that could easily be cut off both by the enemy and the weather. Because of that, a number of river monitors were either constructed or acquired from private owners and armed. They were used on the Pripyat River, as well as its extensive river basin. After the war, some of the ships were returned to their owners, the rest remained on active service and were pressed into the so-called Pinsk Flotilla.

In peace-time the Riverine Flotilla of the Polish Navy, as it was officially called, operated on the Pina River (Dnieper–Bug Canal), as well as on the Pripyat and the Strumień rivers. It served as a mobile reserve of the Border Defense Corps and was to support the front in case of a war with the Soviet Union. Prior to the invasion of Poland, a number of ships of the Riverine Flotilla were moved to the Vistula as a detachment and became Oddział Wydzielony Rzeki Wisły, better known as the Vistula Flotilla.

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