It is now possible to give some information regarding the part played by underwater television in identifying the position of H. M. Submarine Affray, which was lost on Monday, April 16, 1951. The equipment used for this purpose was supplied by Marconi's Wireless Telegraph Company, Limited, Chelmsford, and consisted of a portable camera "chain" the principle part of which was an Image Orthicon pick-up tube, manufactured by the English Electric Valve Company, Limited, Kingsway, London, W.C.2. The camera was built into an underwater container by a team of four members of the Royal Naval Scientific Service who worked on it night and day for three weeks and who also designed the remote controls for operating the equipment.