"The Asknia - United States Device USED To Train British Submarine Crews. 16 and 17 December 1942, Blythe, the Asknia Training Device, Acquired From the United States Under the Lease-lend Agreement, Is An Electro-hydraulic Machine Which Reproduces the Behaviour of a Submarine in Varying Conditions, and Is USED in the Training of Ratings and Officers." A control table of the Asknia training device, showing the silhouette indicator which registers the movements of the submarine.