Germany had invaded Norway, less than 200 miles from Shetland, in April 1940. The Norwegian royal family fled to London, and thousands of Norwegians escaped too, most of them making the crossing to Shetland, usually in fishing boats.
However, a determined resistance movement remained in Norway. The British government wanted to find a way to support those fighters, not least because active resistance would help to tie down nearly 300,000 German troops and reduce their potential for aggression elsewhere.
The chosen solution was the Special Operations Executive, set up on the order of Prime Minister Winston Churchill. It supplied arms, explosives, radio equipment and anything else that the resistance required.
During the second half of 1941, Norwegian fishing boats, crewed by Norwegian volunteers, shipped these essentials to Norway, sailing during the darker – and stormier – winter months to reduce the chances of detection by German patrols.
They landed their cargoes at small ports up and down the coast, seeking to deceive the invaders into believing that they had simply been fishing. The boats also carried agents to and from Norway, bringing out those at most risk, along with refugees. Guns were installed on the boats but, to avoid suspicion, they were ingeniously concealed in oil drums and under nets.