The transport of cargo is not of itself a navigational subject; it is however the purpose of nearly all marine navigation and a development such as ‘containerization’ which is having such a profound effect on the nature of shipping cannot fail to be of interest to navigators at sea. In this paper, a version of which appears on the U.S. North Atlantic Pilot Chart for May 1969, Mr. Van de Ree of the Ship Analysis Division of the U.S. Navy Oceanographic Office describes the background to the development of unitized cargo handling and transportation, its economic advantages and its significance for the pattern of trade at sea.