46 NAUTICAL CHART MANUAL 



ELEVATIONS (D-3, -Da, -Db, -De, Db; 0-1) 



When the information is available, elevations shown on nautical charts shall be referred 

 to Mean High Water and the note "Heights in feet above Mean High Water" shall be used. 

 (See fig. 2.) 



When contour and spot elevations based on the plane of Mean Sea Level are charted, the 

 following note shall be charted: 



HEIGHTS 

 Elevations of rocks, bridges, landmarks 

 and lights are in feet and refer to Mean 

 High Water, Contour and summit elevation 

 values are in feet and refer to Mean Sea 

 Level. 



When elevations are referred to datum planes other than Mean High Water or Mean Sea 

 Level, an appropriate note shall be added to the chart. (See Bridge Clearances, pg. 35.) 



Elevations of summits must be checked with those shown on aeronautical charts, U.S. 

 Geological Survey and Corps of Engineers quadrangles, and those determined by the Division 

 of Geodesy, and every effort must be made to reconcile discrepancies found. 



Elevations of points on slopes shall be omitted. Elevations of tops of trees shall be indi- 

 cated by the overlined slanting figures as shown on Chart No. 1, Item C-11. When used, this 

 symbol shall be added to the General Notes of that chart. Treetop elevations, if available, 

 should be charted on peaks in Southeast Alaska. 



Slanting figures shall be used for all elevations and, wherever possible, summit elevations 

 shaU be so placed that the top of the first figure bears 135° from the position symbohzed by the 

 dot. 



When there is insufficient space to show elevation figures on islets or rocks, they should be 

 indicated by slanting figures in parentheses placed nearby in the water area. 



SAND BEACHES AND DUNES (A^, -6) 



When called for in the Specifications, sand beaches behind the high-water line shall be 

 indicated on the charts. Three rows of dots are sufficient representation in small areas, but 

 for large areas limit lines in blue ink may be shown and the area labeled "Sand" in blue. 



When not too extensive, sand dunes. may be shown along the beach. When the symbol 

 is not used, the area shall be labeled with the words "Sand dunes." 



