BBC Timewatch - The Spies who Fooled Hitler (1999)

Following the occupation of Norway, Denmark, Holland, Belgium and France, the Germans were plotting an invasion of the United Kingdom in 1940 – codenamed Operation Sea Lion – and sent spies to gather intelligence across the English Channel. Operation Lena, part of Hitler's invasion plan, was the infiltration of German-trained secret agents into Britain on sabotage and espionage missions.
The Abwehr, Germany's military intelligence, selected and trained English-speaking Germans, Norwegians, Danes, Dutch, Belgian, French, Cuban, Irish and British men, and a few women. They were either parachuted into remote areas of Ireland or central and southern England, or brought by submarine close to the coast. From there they paddled a dinghy onto an isolated beach in South Wales, Dungeness, East Anglia or Northeast Scotland.