Conquering the sea basins: special expedition for underwater works (EPRON) from the Crimean Balaklava bay to the far eastern Golden Horn Bay (1923-1942)

The article was prepared on the basis of data obtained from federal archives, the Central Naval Museum, St. Petersburg, as well as previously not widely used published documents on the history of the Special Expedition for Underwater Works at the OGPU USSR. The features of the development of EPRON to enlarge and expand the sphere of its influence on the water basins of the Soviet Union (1923-1932) are revealed. Particular attention is paid to the contribution of the Epronovs to the strengthening of the defense potential of the Far East of the USSR (1932-1942). The author comes to the conclusion that having grown stronger and having turned from a local Black Sea organization into an all-Union one, EPRON made a significant contribution to strengthening the defense potential in the tense situation on the Far Eastern borders of the USSR in the 1930s.