18 THE NAVY OCEANOGRAPHIC OPERATIONS PROGRAM 



originated by the Navy in November 1904, whereas the first 

 Notice to Mariners was published in 1848. Courts have held 

 masters of U. S. ships responsible for any casualty due to failure 

 to receive or heed a navigational warning thus issued. 



In fulfilling its mission to provide information and data for the 

 safe navigation of air and surface craft, the Oceanographic Office 

 prepares and publishes a wide variety of navigational publications, 

 including instructional manuals and operational tables. Among 

 the early navigational tables were the azimuth tables for finding 

 the deviation of the compass and for use in determining the best 

 time for sun observations. Other tables were designed for rapid 

 sight reduction, and contained precomputed data with which the 

 navigator compared his observations and established the resulting 

 line of position. 



Although the earliest tables represented considerable progress 

 from the manual Cosine- Haversine solution, they required many 

 rules and instructions. More comprehensive tables soon followed 

 in their wake, catering to the more rapid reduction of sights as 

 required by more rapidly moving ships and aircraft. 



During the decade 1936 to 1945, the Navy published what are 

 historically the most comprehensive tables ever issued for the 

 intercept method of plotting position lines in the practice of astro- 

 nomical navigation at sea. These Tables of Computed Altitude 

 and Azimuth, identified as H. O. Pub. No. 214 (in nine volumes), 

 so far surpassed all others in range and completeness that they 

 became identified with the "tabular method" of sight reduction 

 at sea. Sight Reduction Tables for Air Navigation, H. O. Pub. 

 No. 249 (in three volumes), was first published in 1951-1952 to 

 meet the requirements of military and commercial aviation 

 throughout the world 



In recent years, many navigators and scientists have expected 

 automatic astronomical, electronic, or satellite navigational 

 methods to supersede the older methods of navigation. This 

 expectation has not yet come to pass, and despite tremendous 

 developments in navigational systems of all kinds, including 

 electronic and satellite systems, the need continues for better and 

 faster methods of sight reduction for conventional astronomical 

 navigation purposes. 



