This is the only foreign study that has appeared in the 60 post-war years about the Great Patriotic War in the sea and river theaters. In it, the author, based on the combat documents of former opponents of the USSR and the Soviet military-historical literature available to him, described and analyzed the actions of the opposing fleets, showed the successes and failures of the parties, and also revealed their reasons. For a long time, Yu. Meister’s book, in which the actions of the Soviet Navy are the object of sharp criticism, was a “red rag” for Soviet official historical science, and the author himself was considered one of the prominent falsifiers of the history of the Great Patriotic War. Only now, with the discovery of domestic archival funds and previously secret military-historical research, has it become possible to appreciate this very interesting work. The book is intended for a wide range of readers interested in the history of the Great Patriotic War.