The British hard-chined Coastal Motor Boats of World War I were very fast but required constant attention to trim in order to get the best performance. 1919 saw them in use in a little-known campaign on the Caspian, during the intervention by the Western powers in Russia.
S12 and S13 were part of the first batch of German motor torpedo boats, completed in I 934. Displacing 78 tons, they were 32.3-m (l 06-ft) boats armed with two 533-mm (21-in) torpedoes and a single 20-mm (0.78-in)gun intended for an AA role.
