Operation Tracer was the brainchild of Rear Admiral John Henry Godfrey, the Director of the Naval Intelligence Division of the Admiralty.

[1][2] The facility that was constructed for the top secret, World War II military operation was located near the southern end of the Upper Rock Nature Reserve, in close proximity to Lord Airey's Battery.

It was an offshoot of a larger scheme, entitled the Peripheral Strategy, in which Germany planned to cut Great Britain off from the rest of the British Empire.

[5][8][9] From the observation post in Gibraltar, soldiers sealed inside the cave would report movements of enemy vessels to the Admiralty, using clandestine wireless communication.

British officers, including Commander Geoffrey Birley and chief engineer Colonel Fordham, performed reconnaissance of the Rock of Gibraltar and selected the existing tunnel system for Lord Airey's Shelter as the site of Operation Tracer.

[3][8] Initially, plans were made to provide a year's worth of accommodations for five men, including food, water, sanitation, and wireless communication.

All those involved in the construction of the Operation Tracer facility were immediately returned to England when it was completed, out of concern that they might leak the plan.

Toilets were adjacent to a small radio room that contained the equipment for the wireless communications, which included a Mark 3 transmitter and HRO Receiver.

The entirety of the main chamber had been plastered and its floor covered in cork tiles, both methods to reduce sound transmission.

The report made suggestions as to personnel, exercise, provisions, including food, alcohol and tobacco, ventilation, and sanitation.

At a meeting held the following month, in February 1942, it was recommended that Lieutenant White of the Royal Naval Volunteer Reserve be interviewed.

This again, especially the assembly of the actual stores and the selection of a Signalman is to be treated as a matter of primary importance and a progress report submitted to me on the 24th April.

Levick and five other men of the crew survived their eight-month trip to Cape Evans, which included an entire winter spent in a snow cave, eating seal blubber and penguin meat.

[6] He drew up reports with recommendations for the operation and attended meetings held by the Director of Naval Intelligence at Curzon Street.

Director Godfrey and his consultants agreed with Levick's recommendation for a rehearsal, although Romney Marsh, England, was chosen, rather than a Scotland location.

[5][22] He had been recruited by the Secret Intelligence Service (SIS) in 1938, prior to the onset of World War II, to modernise their radio capability.

When the native of Castle Eden, England, was requested to recommend another physician, he suggested Arthur Milner, a civilian doctor in Morecambe.

The officer apparently had balked at the idea of sharing his dining table with the three naval ratings, the enlisted men who were to serve as wireless operators.

In May 1943 Allied armies completed the capture of North Africa, and on 17 August they drove the last Axis forces out of Sicily, rendering the threat to Gibraltar negligible.

On 24 August 1943, the Director of Naval Intelligence sent a highly classified, one-time pad message in which he ordered one last wireless communications exercise, as well as blocking up of the chambers and distribution of the provisions that had been stored there.

In addition, it has a dozen appendices on food, clothing, utensils, tools, equipment, furniture, cooking, stationery, games, library, sundries, medical stores and surgical instruments.

[8][9][29] After feeling the draught of wind in the tunnel on a levanter day in December 1997, the Gibraltar Caving Group had pushed aside some corrugated metal sheets, and found a bricked-in area of the wall.

During the course of a 28-minute documentary that was filmed and produced in 1998, the team turned on the brass tap over the wash pit supplied by the 10,000 gallon water tank.

The document, which bears a Top Secret stamp in the upper right hand corner, originated from the National Archives in Kew, London.

The respected author and journalist was employed by the Naval Intelligence Division throughout World War II, first under Godfrey and later under his successor Edmund Rushbrooke.

The novel, which detailed the unhappy life of a midshipman in the Royal Navy prior to World War I, was not well received by the Admiralty.

[5][10][31] Researchers Sergeant Major Pete Jackson of the Royal Gibraltar Regiment and Jim Crone interviewed retired Surgeon Lieutenant-Commander Bruce Cooper in England in November 2006.

[2][18][34] During his visit to Gibraltar, Cooper stayed at the Rock Hotel, the same place he had resided more than sixty years earlier when he first arrived for his covert mission.

Prince Edward and his wife had the opportunity to visit the Upper Rock and tour Operation Tracer's Stay Behind Cave.

Martin Nuza, of Gold Productions Studios, has formed a partnership with producer James Davidson to develop a film based on the story of Operation Tracer.