232 



HYDROGRAPHIC MANUAL 



within the common area. In this case the 

 superseded area shall be delimited by a 

 dashed line and labeled "Superseded by 

 H (19—)". 



Junctional notations and transferred 

 soundings shall be in color (Fig. 82, 83). 

 A different color should be used to ink trans- 

 ferred soundings from consecutive adjoining 

 surveys. The preferred ink colors are car- 

 mine red, red violet, orange, and brown in 

 that order. Blue and green should be avoided 

 as they photograph poorly under routine 

 procedures. In wire-drag areas the green 

 color shall be reserved for transfer of wire- 

 drag soundings. 



Depth curves shall be drawn so that there 

 is a definite continuity and curves in the 

 area of overlap shall be made to agree. This 

 does not mean that supplemental curves on 

 each sheet shall be added to the other. 



6-92 Preliminary verification. — Com- 

 plete inking of the smooth sheet can usually 

 be accomplished during verification. Where 

 scheduling does not permit the complete ink- 

 ing, authorization may be given for a pre- 

 liminary verification of relatively simple 

 surveys of uncongested areas. Under this 

 procedure only a pattern of lines sufficient 

 to assure the general accuracy of depths is 

 verified and inked. Other hydrographic in- 

 formation to be verified and inked include 

 least depths on important features, question- 

 able depths not supported by other sound- 

 ings, and positions of piles, obstructions, 

 rocks awash, etc. The survey is inspected 

 for crossing discrepancies, misplotting of 

 sounding lines, unnatural delineation of the 

 bottom, or other indications of errors, and 

 the verification and inking necessary to 

 eliminate these inconsistencies is accom- 

 plished. The depth curves are not inked and 

 junctional soundings are not transferred to 

 the sheet until a later date. The preliminary 

 verification should cover all critical details 

 essential to safe navigation and should be 

 adequate for complete application of the sur- 

 vey to nautical charts. At a suitable time 

 the verification and inking of the survey 

 will be completed and an addendum com- 



pleting the review will be added to the de- 

 scriptive report. 



6-93 Sheet clean up. — After completion 

 of verification and inking of the smooth 

 sheet, extraneous notes and marginal soiling 

 should be removed by careful erasing, and 

 it may be advisable to use an artgum eraser 

 to eliminate some of the pencil graphite 

 smear on the sheet. Care shall be taken that 

 inked soundings are not impaired. In some 

 congested areas on sheets occasionally pen- 

 ciled too dark during smooth-plotting it may 

 be advisable to use the artgum eraser lightly 

 before inking. This procedure permits the 

 ink to penetrate the sheet instead of produc- 

 ing a thin flaky coating over the graphite- 

 coated paper. 



6-94 Verifier's reports. — Two forms are 

 inserted in the descriptive report for use of 

 the verifier and reviewer. The first is a 3- 

 page check list. Form 946A, titled "Veri- 

 fier's Report of Hydrographic Survey H, " 



on which the verifier indicates that all es- 

 sential actions have been performed. Space 

 is provided under each heading for inser- 

 tion of notes and information which will 

 assist the reviewer, who is guided by it and 

 abstracts pertinent parts to his review report. 



The second report, Form 946, is a statisti- 

 cal report on which is shown the time spent 

 in verification and review of the survey and 

 the amount of revision required in the var- 

 ious phases of smooth plotting. 



6-95 Plot of additional work. — Supple- 

 mental hydrography accomplished in accord- 

 ance with instructions from the Washington 

 Ofl[ice is sometimes received after the survey 

 has been smooth plotted. If this information 

 is smooth plotted before formal administra- 

 tive approval of the survey, it is verified and 

 inked in black as part of the original survey. 

 But when the hydrography is received after 

 formal administrative approval of the sur- 

 vey, it is considered "additional work" of a 

 specific year. In order to avoid sending the 

 permanent copy of the survey away from 

 the Washington Office, the smooth plotting 

 of additional work is usually accomplished 

 in the Verification Unit. During verification 



