The aim of this paper, which was presented to the last meeting of Icotas (London, 14 January), is to show how the manœuvres proposed by Calvert (Journal13, 127) and by Hollingdale (Journal14, 243) could be incorporated in the International Regulations for Preventing Collisions at Sea. Calvert's objective was, as Hollingdale points out, to establish a set of manœuvres whereby a collision situation may be converted into a ‘miss’ of specified magnitude.