4 NAUTICAL CHART MANUAL 



II 

 Compilations 



All information shown on the charts, except revisions applied directly from air photo- 

 graphs to Drawings by the Division of Photogrammetry, is compiled by the Nautical Chart 

 Division and furnished the Reproduction Division in one of the following categories: 



NEW CHARTS 



Compilations of New Charts are drawn on sheets of transparent stable plastic. Black 

 ink is used for black plate information; green ink is used for detail to be printed in magenta. 



Type should be placed directly on compilations of New or Reconstructed Charts that are 

 to be engraved on glass, and on smooth-drafted compilations intended for direct reproduction. 

 An optional method, requiring advance approval, is to place the type on a transparent overlay. 



RECONSTRUCTED CHARTS 



When the accumulation of new information is sufficiently extensive to affect most of an 

 existing chart, the chart may be completely recompiled on a new projection. This Reconstructed 

 Chart is processed in the same manner as a New Chart. 



When only the topography is to be reconstructed, a projection is drawn on a sheet of trans- 

 parent stable plastic and the new topography is compiled on it in black ink. This is then 

 combined with the present hydrography to make a composite compilation. 



Minor corrections to other color plates shall be made in green ink on the reconstruction 

 compilation. 



DRAWINGS 



At the completion of the paper press run of all black and magenta nautical chart printings, 

 an impression of each of these two colors is printed on separate sheets of matte finish transparent 

 plastic. These prints are forwarded to the Nautical Chart Division where they are designated 

 as Drawings and filed for use in revising subsequent chart printings. Revisions to the black 

 Drawing are made in red ink. Revisions to the magenta Drawing are made in green ink. 



