This post is seventh in a series drawn from a History of I.S.9 (CMF) in the British National Archives. Research courtesy of Brian Sims.
Below is a transcript of the section of the history detailing rescue efforts and drop of stores and supplies into enemy occupied territory:
Sea Borne Operations
Subject to enemy defences and weather, sea borne operations for landing personnel are not normally very difficult.
The one great stumbling block to pinpoint landings and certainly to evacuation by sea, is pinpoint navigation. Normally vessels must operate during the non moon period and to arrive at a given time at a given pinpoint on a long stretch of coast without distinctive landmarks, is extremely difficult.
Native pilots of course are invaluable, but even these find it difficult to navigate on a dark night to one given pinpoint on a long straight stretch of coastline. Given the use of naval craft fitted with the latest radar, the problem is less difficult, but where schooners, fishing boats, etc., are used, pinpoint navigation is difficult. One answer, under these conditions, is the use of a homing beacon tuned to a radio compass fitted to the vessel to be used. This homing beacon means, of course, an extra piece of equipment with necessary batteries and aerial which must be carried by the shore party.
This is by no means impossible where the operation calls for a short stay inside E.0.T. [enemy occupied territory] and where a safe house is known, but it is not so simple where the operation calls for Agents to be infiltrated a long time ahead of any proposed evacuation and where much movement and travel is required to be carried out by the infiltrated party.
The answer would seem to be to adapt the small portable transmitter/receiver normally carried by Agents on a common frequency to that of a radio compass. This would appear to present no great difficulty.
It does mean, however, that either all such motor fishing boats, schooners, etc., to be used must be fitted with a radio compass or that a portable radio compass with director aerial would have to be made up and be transportable for use on any boat used for evacuation. Experiments already carried out by I.S.9 leads one to suppose that this aid to pinpoint navigation can be used. Walky-Talkies from shore to ship are extremely useful but here again this means extra equipment for the Agent to carry in E.O.T.
Our reader then, having, it is hoped, absorbed enough background of the rather peculiar organization known as I.S.9 (CMF), should continue with his reading of the following chapters in which are recorded the operations carried out in the Countries which became the responsibility of I.S.9 (CMF) for E & E work.