Military applications in the Second World War Radio control was further developed during World War II, primarily by the Germans who used it in a number of missile projects. Their main effort was the development of radio-controlled missiles and glide bombs for use against shipping, a target that is otherwise both difficult and dangerous to attack. However by the end of the war the Luftwaffe was having similar problems attacking Allied bombers, and developed a number of radio-controlled anti-aircraft missiles, none of which saw service. The effectiveness of the Luftwaffe systems was greatly reduced by British efforts to jam their radio signals. After initial successes, the British launched a number of commando raids to collect the missile radio sets. Jammers were then installed on British ships, and the weapons basically "stopped working". The German development teams then turned to wire guidance once they realized what was going on, but these systems were not ready for deployment until the war had already moved to France. The German Kriegsmarine operated FL-Boote (ferngelenkte Sprengboote) which were radio controlled motor boats filled with explosives to attack enemy shipping from 1944.