The S-Boot class 1939/1940 was the largest class of fast attack boats built in Germany during the war. Built between 1940 and 1945, those boats were modified based on the experience of war action, especially the light flak armament was tripled in the later boats. Powered by the 20 cyl Daimler Benz Diesel, they were able to archive speed above 40 kn.

From S100 on, the boats were equipped with an armored control platform to protect the crew from attacks of British MGB and MTB.

Most of the more than 100 boats built were lost during the war, either through mine hits, battles with British ships or air attacks. The surviving boats were given to various countries after the war, the Soviet Union used several of them until the 1950, other boats were given to Norway or Denmark. Some few boats were later returned to the German Bundesmarine where they served as experimental ships.