In a valuable paper published in July 1960 (Journal, 13, 253) Hanssen and James described the system developed by the U.S. Hydrographic Office (now U.S. Navy Oceanographic Office) for selecting the optimum track for transoceanic crossings by applying long-range predictions of wind, waves and currents to a knowledge of how the routed vessel reacts to these variables. In the present paper the authors, both of the Marine Sciences Department of the U.S. Navy Oceanographic Office, propose a method, based on this earlier work, of using climatic charts on the North Atlantic to avoid regions of high frequency storm conditions and thus improve ship efficiency. Essentially this method is for ships not being routed by a central forecasting office. An earlier version of the paper appeared on the verso of the U.S. North Atlantic Pilot Chart for March 1969.