TOPOGRAPHY 41 



Some New Charts and corrections to existing charts are compiled directly from the photo- 

 graphs. When this is done, it is the responsibility of the nautical cartographer to see that the 

 topographic delineation is clear and appropriate. Notes in blue ink shall be added to the 

 Drawings to clarify questionable detail for the engraver. To indicate tint colors on the Draw- 

 ings, the letters "Ma" shall be used for green (marsh tint), "W" for blue (lakes and ponds), and 

 "B" for buff (land tint). While it is sometimes necessary to clarify corrections by showing 

 the tints in color on the Drawings, it is not desirable because the colors photograph on the 

 reproduction negatives and obscure the line detail. This method of indicating tints should 

 be avoided where possible; but, if used, the colors should be lightly shaded. 



It shall be the duty of the engineer to indicate in the Specifications the detail to be charted 

 and the symbolization to use. Consideration must be given to the chart scale and the purpose 

 for which the chart is being constructed. In general, on large-scale charts complete topographic 

 detail should be shown along the coast for several miles inshore, while on small-scale charts 

 most of the detail inside the high-water line should be omitted. 



On compilations and on final charts the outer coastline and important rivers are shown 

 by the maximum weight line (.011"), but streams and unimportant indentations are shown 

 by thinner lines. In a dense drainage system, minor streams are omitted. 



Physical features, such as gravel, brush, trees, etc., generally are not shown by symbols, 

 but are indicated by name. 



Symbols used on the charts of this Bureau are shown on Chart No. 1, "Symbols and Abbre- 

 viations," and Figiu-e 1 in the Appendix of this manual. A few of those symbols which need 

 emphasis are discussed on the following pages. 



Natural Features and Relief 



HIGH WATER LINE (Fig. 1) (A-9) 



The shoreline shown on the charts is the mean high-water line except in marsh or man- 

 grove areas where the outer edge of vegetation (berm line) is used. It shall be represented 

 by a .011" line which shall gradually decrease up streams and rivers. Unsurveyed shoreline, 

 or shoreline connecting two surveys which do not join satisfactorily, shall be represented by a 

 dashed line. The outer limits of marsh shall be indicated by a .006" continuous line. 



