Another class of small fast attack boats were the so called "Küsten-Minenleger". Those boats were designs as offensive mine layers which should be able to carry up to 4 mines and operate close to enemy coastlines. Therefore the boats were very small (less than 16 meters) to be able to operate unseen from enemy forces. Because of their small size, those boats were not able to fight other ships, their only defense was their size and speed to evade.
A total of 36 boats were ordered, but because of their unreliable engines, none of them was used in original planned role. Instead, they were used to operate in lakes, rivers and coastal areas at the eastern front. Since they were not used as mine layers, 20 of the boats were equipped with torpedo tubes and operated as fast attack boats. The other ones were used as mine hunters.
Almost all of the boats survived the war, many of them were taken over by the soviet Union in 1945, but their fate is unknown.