The agents were mostly Polish, Estonian, Latvian and Lithuanian exiles who had been trained in the United Kingdom and Sweden and were to link up with the anti-Soviet resistance against the communist governments (the cursed soldiers, the Forest Brothers).

The operation was codenamed "Jungle" and led by Henry Carr, director of the Northern European Department of MI6, and Baltic section head Alexander McKibbin.

[1][5] Agents were inserted into Saaremaa, Estonia, Užava and Ventspils, Latvia, Palanga, Lithuania and Ustka, Poland, typically via Bornholm, Denmark, where the final radio signal was given from London for the boats to enter the territorial waters claimed by the USSR.

The boats proceeded to their destinations, typically several miles offshore, under cover of darkness and met with shore parties in dinghies; sometimes returning agents were received at these rendezvous.

The "British Baltic Fishery Protection Service" was thus invented as a credible cover story given the harassment of West German fishermen by the Soviets.

The operation evolved with a secondary task of visual and electronic reconnaissance of the Baltic coast from Saaremaa in Estonia to Rügen in East Germany.

For this purpose the boat was re-fitted with additional fuel tanks for extended range and an extensive antenna suite and American equipment for COMINT and ELINT.

[1] In August 1952, a second E-boat was put into service as a refuelling and supply vessel and consort for the SIGINT operations, under the command of Lieutenant E. G. Müller, a former executive officer who served under Klose during World War II.

[6][1] They were built at the Lürssen dockyard in Bremen-Vegesack for the West German Border Police, but under the pretense that the boats exceeded the speed allowed by the treaty of Potsdam, French and British authorities confiscated the vessels for Klose's missions.