751 



HYDROGRAPHIC MANUAL 



Page 692 



derived from the topographic survey, so that they are correct and in agreement with 

 data originating with the hydrographic survey (see 381). 



In order that the hydrographic survey may present a complete graphic record of 

 the area, all topographic details within the limits of the hydrography and adjacent to it, 

 including the high-water line, must be shown on the smooth sheet except as noted in 751. 



The transfer of the topography must be made with the utmost care so that there 

 is no appreciable inaccuracy in position. Photographic copies of the hydrographic 

 surveys are frequently furnished to the public and to governmental agencies, and it is 



Figure 155. — Shoreline shown on smooth sheet without obscuriag positions of control stations. 



naturally assumed by many of these that the topographic details shown thereon are 

 correct. 



When the topography is transferred, the high-water line and all offshore details 

 are transferred at the same time in pencil, but are inked only as specified in 752 to 755 

 inclusive (see also table 28) . Topographic detail must never obscure the centers of con- 

 trol stations. Only important detail should be shown inside the station symbol, but in 

 no case shall the shoreline be drawn through the station point. Examples to be followed 

 are illustrated in figure 155. 



Topographic details inshore from the high-water line shall be omitted from the 

 smooth sheet, except where stations are on or near buildings (see 7844). 



751. Omission of Topography 



The field plotter may omit all or part of the topography from the smooth sheet in 

 the following cases: 



(a) Where there is no contemporary topographic survey. After the hydrographic survey has 

 been reviewed in the Washington Office, a decision will be made as to whether any topography is to 

 be shown thereon. 



(6) Where the topographic and hydrographic surveys are on different scales and the transfer 

 presents difficulties. In such cases the topography wiU be added to the sheet at a later date in the 

 Washington Office. 



