166 



HYDROGRAPHIC MANUAL 



EDO-255 echo sounders shall be recorded on 

 the right hand page of the sounding record 

 as they are made. 



All standardizations and comparisons re- 

 corded in a sounding volume shall be prop- 

 erly indexed in the front of the book for 

 easy reference when the data are sum- 

 marized at a later date. 



5-94 Preliminary run and weather. — The 



time the party got underway or left head- 

 quarters and the distance in nautical miles 

 to position 1 of the day's work shall be en- 

 tered in Stamp No. 34 (Fig. 62). The state 

 of the weather, wind and sea shall also be 

 entered in this stamp. Any change in the 

 weather shall be noted in the remarks col- 

 umn. If hydrography is continuous on a 24- 

 hour basis, the state of the weather, wind, 

 and sea shall be recorded at the beginning 

 of each watch using Stamp No. 20 (Fig. 63). 

 Stamp No. 34 shall also be used at the end 

 of the day to enter the distance from work 

 and the time of arrival at the anchorage or 

 headquarters. 



5-95 Column entries. — Figures 64 to 66 

 illustrate the methods of recording data for 

 a hydrographic survey. The pages of the 

 sounding record are ruled into headed col- 

 umns. It is important that each entry be 

 made in the correct column and that entries 

 do not encroach on adjacent columns. All 

 of the data which are related to a specific 

 time entry shall appear on the same horizon- 

 tal line, except that where more than one 



No. 34 Depart Arrive Distance 



Anchorage QiifiQ, Mi. 



Working grounds Q.JSJO. /^...^..Mi. 



Underway at _ Weather. .C./iPi^^. 



..N.E..3 iti.Mt:.c:Ko, 



Wind.. 



l.Q/?.. 



Figure 62. — Stamp No. 34 with entries properly 

 made. 



No. 20 



Weather Cledf 



Wind A/£ //- 



Sea. Mods. roL-he. 



Figure 63. — Facsimile of Stamp No. 20. 



line is required to enter the data only the 

 first entry falls on that line. Miscellaneous 

 entries in the remarks column may be re- 

 ferred to their respective times by the use of 

 corresponding reference marks at both. Nu- 

 merals should not be used for this purpose. 



Positions shall be numbered consecutively 

 starting with number 1 at the beginning of 

 each day (see 5-34). These position num- 

 bers shall be entered in the column headed 

 "Position Number" on the left and right- 

 hand pages and on the same line with the 

 time of observation. No other entries shall 

 be made in these columns. 



Standard time shall be used in all hydro- 

 graphic recording and the standard meri- 

 dian shall be noted at the head of the time 

 column at the beginning of each day's work. 

 Time shall be recorded by numbering the 

 hours consecutively from (midnight) to 

 23 (11 p.m.). All times shall be recorded in 

 the "Time" column with the corresponding 

 data to which they refer entered on the same 

 horizontal line. The exact time of each posi- 

 tion, each regular interval sounding, and 

 each entry that is used in plotting, must be 

 recorded. Soundings at peaks and deeps 

 which are recorded between the soundings 

 recorded at regular intervals may be timed 

 as a fraction of the interval, as %, V^, etc., 

 or the time may be recorded as scaled from 

 the fathogram. 



All times shall be recorded from a care- 

 fully regulated clock (see 3-110). Echo 

 sounders are designed to operate at a con- 

 stant speed, but they are not designed to 

 measure time and shall not be used in lieu 

 of a clock. The clock shall be set to the 

 correct time at the beginning of the day and 

 shall be compared with the standard at the 

 end of the day. Any gain or loss of time 

 shall be recorded. When survey operations 

 involve the use of two or more clocks, as in 

 EPI controlled surveys, the clocks shall be 

 set correctly at the beginning of the day and 

 verified at least once each watch throughout 

 the day (see 3-32). 



Soundings shall be entered in the double 

 column headed "Soundings." If the bottom 

 is generally even so that only a few soundings 



