SURVEYING THE OCEANS (HYDROGRAPHIC) 27 



SURVEYING FOR NAVIGATIONAL HAZARDS 

 (PORT, HARBOR, AND COASTAL) 



Highly skilled personnel— both military and civilian— using 

 specially equipped ships and auxiliary sound boats conduct hydro- 

 graphic surveys primarily in waters outside the United States 

 and its possessions to acquire information needed for producing 

 charts of ports, harbors, and coastal areas. Although the depth 

 of water is of primary concern, the surveys also delineate the 

 coastlines; position dangers and aids to navigation; collect tide 

 and current information; establish heights of conspicuous land- 

 marks; and gather bottom samples, weather information, and a 

 variety of other data necessary for a complete description. During 

 the past two years, the Navy's somewhat limited coastal survey 

 capability has been committed to direct support of the military 

 effort in Southeast Asia. Approximately 50,000 miles of controlled 

 survey track have been run, providing vitally needed information 

 for new charts of the area. Recently completed coastal surveys 

 have also resulted in new charts of portions of the coasts of 

 Greece, Colombia, Johnston Island, and Subic-Manila Bay of the 

 Philippines. 



In late 1964, the Navy initiated its Harbor Survey Assistance 

 Program (HARSAP). This program has the dual purpose of 

 helping friendly countries develop their own hydrographic sur- 

 veying capability while at the same time ensuring issue of new 

 or improved charts. The program has been successful from the 

 beginning, and HARSAP surveys in Ecuador, Guatemala, El 

 Salvador, Nicaragua, and Colombia are resulting in charts that 

 meet established standards. Not only are much needed charts 

 acquired at a relatively low cost, but the participating nations now 

 have the capability to chart their own waters— thus favorably 

 influencing shipping insurance rates and stimulating their 

 foreign commerce. 



PHOTOGRAMMETRY AND AERIAL PHOTOGRAPHY 



Photogrammetry, the science of making precise measurements 

 from photographs, has been used in charting operations from at 

 least the mid-1880's, when panoramic terrestrial photographs 



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