20 THE NAVY OCEANOGRAPHIC OPERATIONS PROGRAM 



corresponding to the time difference readings obtained with a 

 Loran receiver. 



Loran (LOng RAnge Navigation) is an electronic navigation 

 system that provides for rapid and accurate position fixing by 

 air and marine navigators, especially in areas of poor visibility or 

 other areas where normal methods fail. The system was developed 

 during World War II by the Radiation Laboratory of the 

 Massachusetts Institute of Technology, in collaboration with the 

 Navy. The necessary computational techniques, tables, and charts 

 needed for effective use of the new system were developed and 

 perfected and the voluminous computations carried out by the 

 Navy. Tables for other electronic navigational systems that may 

 be developed for marine navigational use will be developed and 

 published by the Oceanographic Office as part of its statutory 

 mission. 



Volumes of the Sailing Directions contain navigational infor- 

 mation that facilitates the navigation and operation of ocean-going 

 ships in unfamiliar waters. In addition to presenting information 

 that cannot be shown on charts, they supplement, interpret, and 

 clarify, where necessary, charted information. Their publication 

 fulfills that part of the statutory mission of the Oceanographic 

 Office which specifically requires publication of sailing directions 

 in the interest of safe navigation. 



Sailing Directions were first published in the 1840's and 1850's 

 to accompany the famous "Wind and Current Charts" of 

 Lieutenant Matthew Fontaine Maury, U. S. N., who is often 

 referred to as the "Founder of the Science of Oceanography". 

 Each of the 69 volumes on issue today contains, for specific foreign 

 areas, detailed descriptions of the coasts and harbors of the foreign 

 waters of the world. Included are details on channels, dangers, 

 aids, winds, currents, tides, port facilities, signal systems, pilotage, 

 directions for approaching and entering harbors, and a host of 

 other material. 



Sailing Directions are complemented by a variety of other 

 navigational guides and manuals. These include such items as 

 Fleet Guides which provide U. S. naval ships with pertinent navi- 

 gational information for the various naval bases. The List of 

 Lights and Fog Signals (in seven volumes) has been published 



