A draft of this paper was circulated for the open meeting of the Technical Committee on 17 May 1972, when the forthcoming revision of the Collision Regulations by Imco was discussed (see page 427).

Radar has been in general use in merchant ships since the end of the Second World War and during this time the Regulations for the Prevention of Collision at sea have undergone two amendments at International Safety Conferences, in 1948 and 1960. The amended regulations were ratified and brought into use in 1954 and 1965 respectively. The 1948 regulations made no reference to the use of radar whatsoever—radar for commercial use was still in its infancy in 1948 and indeed little was then known about its capabilities and limitations, nor of the operational difficulties it was going to present even before these 1948 regulations were finally ratified in 1954.