On the night of October 13-14, 1939, the German submarine U-47 was able to break through to the raid of the main base of the British Navy - Scapa Flow. The official German report stated that as a result of the raid, the battleship Royal Oak with a crew of 1,200 people was sunk and the battle cruiser Repulse was damaged. The British responded by saying that the Repulse was at sea. Decades passed, and the question remained open. Alexander Korganov conducted a real investigation, during which he was able to meet not only with the surviving crew members of the battleship and submarine, but also with the author of the idea of this attack - Grand Admiral Karl Doenitz, who spoke of this book as a fascinating and truthful story. Alexander Sergeevich Korganov, born in Paris into a Russian family of emigrants of the first post-revolutionary wave, received a law degree, then served in the French merchant fleet, and subsequently headed the development of promising projects for underwater weapons systems. A major specialist in the field of underwater technologies, including in the field of hydrodynamics and propulsion systems. Author of many books and publications on special technical and historical topics. His monograph “Submarines” is considered one of the best in this field. For more than ten years he published the magazine “Revue Forces Sous-Marines”, which had international recognition.