824 HYDROGRAPHIC MANUAL Page 774 



on the particular survey sheet. Those reduced soundings that are in the unit which 

 is not to be used, shall be converted to the appropriate unit in accordance with the 

 conversion tables in 7716, the results being entered in the double column headed 

 "Office." The unit must be indicated by drawing lines through the inapplicable sub- 

 headings at the top of the double column. 



The result will be that the right-hand entries on the left page of the Sounding 

 Record will be in the same depth unit^ — ^that to be used in plotting the smooth sheet. 



824. Verification of Reduced Soundings 



The entries of the various corrections (822) and the reduction of the soundings and 



the final reduced soundings shall 

 be checked. To indicate that 

 this has been done, a checkmark 

 shall be placed opposite each 

 correction entry and at the bot- 

 tom of each column of reduced 

 soundings. If there are numer- 

 ous correction entries in a col- 

 umn, one checkmark at the bot- 

 tom of the column will suffice. 

 Rubber Stamp No. 38, Process- 

 ing (fig. 183), shall be impressed 

 at the end of each day's record, 



FIGURE 183.- FacsimOe of Processing stamp with entries properly made. ^^^ ^^^ ^.^.^jg ^^ ^^^ pei"SOns 



who made the original entries and of those who checked them shall be entered in the 



appropriate spaces. 



825. Errors Detected During Plotting 



In spite of the fact that all correction entries and all reduced soundings are checked 

 in the field, serious mathematical errors have been found during the smooth plotting. 

 The entry of the tide leducers is the only step in the reduction of the Sounding Record 

 which is checked at the Washington Office. This is done because the plane of reference 

 may be known more accurately after the receipt of the Sounding Records, but not to 

 provide an additional check. 



Mathematical errors found during the smooth plotting shall be corrected, but no 

 other deviation from the Record shall be made unless it is reasonable and supported con- 

 clusively by other evidence. All corrections made on the left-hand page of the Record by 

 the smooth-sheet plotter shall be made with colored pencil and be fully explained or 

 justified by a note in the "Remarks" column. The Record and the smooth sheet, when 

 completed, must be in full agi'cement. (See also 774.) 



83. MISCELLANEOUS RECORDS 



When a hydrogi-aphic survey was relatively simple, as before the advent of echo 

 sounding and Radio Acoustic Ranging (R.A.R.), the Soundmg Record usually sufficed for 

 the entry of all the hydrographic data. Due to the complexity of modern hydrographic 

 surveys — particularly offshore ship surveys — there are essential data which cannot 

 conveniently be included in the Sounding Record, but which form a part of the 

 permanent records. It is with these miscellaneous records that this section deals. 



