The Chief Marine Superintendent of BP Tanker Co. and his Electronics Superintendent examine cost–benefit analyses of expenditure on improved navigational aids as part of a broader study which includes a technical appreciation of individual items of hardware and their contribution to the navigational package. It is suggested that the range of modern, and in many cases complex, aids now available needs careful scrutiny before the optimum outfit for a given vessel may be selected. This paper was read at a meeting of the Institute in London on 19 December 1973 with the President in the Chair.