Ensign of Polish river Army ships (not naval river ships). Based on Image:Naval_Ensign_of_Poland.svg and Image:Anchor pictogram.svg. This ensign was used since 1930 to 1938.
Adam Kromer - "Polskie flagi..." flaga wojskowych statków żeglugi śródlądowej 1930-1938.
Naval_Ensign_of_Poland.svg
Anchor_pictogram.svg
Naval_Ensign_of_Poland.svg: Denelson83, Mareklug, Wanted
Anchor_pictogram.svg: egg extracted the symbol out of the coat of arms
derivative work: Mboro (talk)