Limpet Mine

It is known that Limpet mines were issued to some Patrols, especially those near to important rivers eg. Stoke Gabriel on the River Dart in Devon, for use on enemy shipping.

These were made of 6 limpet mine magnets, (shown) arranged in two rows of three magnets, on a frame, with the Limpet in the centre.

A full example is displayed at Imperial War Museum.

In the War Diary of Military Intelligence (Research) it is stated they were developed by Major M. R. Jefferies and were being produced by November 1939.