HYDROGRAPHY 63 



Controlling depths shall be given in feet only, and shall not be greater than project depth. 

 However, tabulated depths should agree with those disseminated by the Corps of Engineers. 



The procedure for charting and publishing controlling depth information is as follows : 

 1. Nautical Charts 



a. Full tabulations for the four quarters 



To be used when adequate information is available and conditions of the improve- 

 ment warrant. The surveys received with the tabidated depths from the Corps of En- 

 gineers shall always be used to ascertain the best method of presenting the controUing 

 depth information to the public. Shoals along the edges of the channels should be de- 

 scribed by a footnote. 



Controlhng depths in the tabulated form, based on actual surveys, shall not be 

 superseded by examinations consisting of a few lines only. Such reports shall be taken 

 care of by a footnote. 



b. 27 FEET FOR MIDDLE WIDTH OF 150 FEET JAN 1963 



This form shall be used for channels 100 feet wide and greater when the tabulated 

 form is not considered justified, and when there are shoals in the outer quarters near the 

 edges of the channels. 



The controUing depth shall be given as near the project depth as possible, and shall 

 be for the greatest available width. Consideration shall be given to the draft of the 

 vessels expected to use such channels when selecting the depth and width to be charted. 



When the available width closely approximates the project width, the word MIDDLE 

 may be omitted. 



C. 27 FEET FOR WIDTH OF 50 FEET JAN 1963 (see note) 



This form shall be used when the controlling depth is given for the middle 80 percent. 

 In this case, when the information is available, the depths in the outside quarters 

 shall be stated in the Notice to Mariners. 



d. 5 FEET 



This form shall be used when no information is available as to the date the controlling 

 depth was determined or the width to which it appUes. 



e. When no recent information is available relative to an improved channel charted 

 by dashed Hues, consideration should be given to removing the channel lines and adding 

 soundings and depth curves. Channels classified by the Corps of Engineers as inactive 

 fall in this category. 



Soundings and curves should also be used for those channels for which infrequent 

 surveys are received provided the scale of the chart is such that soundings and curves 

 would better depict the bottom configuration. 



692-834 O - 64 - 6 



