About the book: 1957 / Publisher's abstract: The book describes the actions of underwater saboteurs (crews of midget submarines, man-controlled torpedoes and specially trained combat swimmers) used during World War II in the navies of most capitalist countries. Underwater saboteurs were used mainly for the purpose of mining enemy ships hidden in their bases, and in some cases in neutral ports. In addition, they conducted reconnaissance off the enemy’s coast and acted to eliminate artificial obstacles.