This book is a rare look at Soviet combat divers from the 1930s up to the end of World War II. The initial formation of the military diving services, including diving reconnaissance and sabotage units of the navy, and Red Army during the prewar years are described in detail. The training of divers during the war years - including underwater exploration and sabotage, mine clearance, emergency rescue, diving support landings, and river crossings - as well as their operational combat use from the Baltic Sea to the Black Sea, is also presented in concise detail. The highly informative description of the diving gear, weapons, and equipment used by divers-scouts and saboteurs features many photos, many of which are published here for the first time.