Don't eat Benbecula fish
A lot of 7 Sqn Rushton sorties were out of Kinloss to the Benbecula range.
For a while we used a device called RAMDI. Radioactive Miss Distance Indicator. A small geiger counter placed in the body of the Rushton which could pass information down the cable to the Canberra crew.
A small radioactive particle was placed in the nose of the Rapier. If it passed close to the Rushton we obtained a readout of distance.
I wonder just how "trace" that particle was if it could be detected at 20ft whistling past at 600kts.