14-160 Hour. — Record the hour and minute 

 for the beginning of the current fix; i. e., the 

 start of the 4-minute run on the initial base 

 course. Use Greenwich mean time (GMT). 



14-161 Vertical Magnetic Intensity. — The 

 vertical magnetic intensity is the value of the 

 nearest standard isodynamic line as indicated 

 by H. O. Chart 1702, The Vertical Intensity 

 of the Earth's Magnetic Force, for the appro.xi- 

 mate position of the current fix. 



(a) Stand. (I). — The H^ dial setting of the 

 GEK at the time of the current fix is recorded 

 in this column. 



(6) Local. (II). — The standard isodynamic 

 value for the position of the current fix is 

 recorded in this column. Record this value to 

 the nearest 0.005 oersted. 



14-162 Wave Signal Supp.— The wave 

 signal suppression is the record of the total 

 amount (in C units) of wave supression in use 

 during the current fix. This is indicated by 

 the setting of the filter resistance dial on the 

 GEK. This value is also recorded on the GEK 

 recorder chart. 



14-163 Initial Base Course.— The initial 

 base course is that course the ship is steering 

 prior to the first course change of the current 

 fix. The direction (III) is recorded in degrees 

 true. The signal (IV) is recorded in centimeters 

 per second and is obtained from the trace on the 

 GEK recorder chart during the four minutes 

 prior to the first course change. 



14-164 First Fix Course. — The direction 

 (V) of the first fix course is the first course 

 change from the base course. It is 90° to the 

 right, or left, of the base course. Record the 

 time of the course change on the GEK recorder 



chart. The signal (VI) is that indicated by the 

 trace. 



14-165 Second Fix Course. — The direction 

 (VII) of the second fix course is the second 

 course change from the base course. It is 180° 

 from the first fix course, with the turn being 

 made in the direction of the base course. Re- 

 cord the time of the course change on the GEK 

 recorder chart. The signal (VIII) is that indi- 

 cated by the trace. 



14-166 Resumed Base Course. — The direc- 

 tion (IX) of the resumed base course is the same 

 as the initial base course. It is 90° to the right, 

 or left, of the second fix course. The signal (X) 

 is that indicated by the trace during the first 4 

 minutes after the electrodes have steadied on 

 the base course. 



14-167 Depth of Water.— Record in 

 fathoms the sonic depth of the water at the 

 time of the current fix. 



14-168 Position of Current Fix. — Record 

 the corrected ship's position for the time at the 

 beginning of the current fix. Latitude and 

 longitude are recorded in degrees and minutes. 

 Be sure to indicate whether N or S latitude and 

 E or W longitude. 



14-169 Ship's Average Speed. — Record the 

 ship's average speed, in knots, during the cur- 

 rent fix. 



14-170 Observer's Initials. — The observer 

 logging the current fix should initial both the 

 log sheet and the GEK recorder chart. 



14-171 Remarks. — Use a whole line, or 

 lines, under the current fix data to note any 

 remarks that may be of help in later analysis 

 of the data. 



OCEANOGRAPHIC LOG SHEET GEK 2, PRNC-NHO-1336a 

 (Rev. 6-54) 



ELECTROMAGNETIC CURRENT COMPUTATIONS 



14-172 GENERAL REMARKS.— The GEK- 

 2 sheet is used to record computations from 

 surface current data given on the GEK-1 sheet. 

 Instructions for operating the GEK are given 

 in chapter 9. Study those instructions care- 

 fully before using this log sheet. 



14-173 THE LOG SHEET.— A sample log 

 sheet is shown in figure 14-9. Print all entries 

 accurately and neatly. 



14-174' The Log Sheet Headings.— Fill in 

 the ship's name and number, cruise name and 

 number, and the GEK instrument number in 

 the proper spaces. 



152 



14-175 The Log Sheet Columns.— The log 



sheet columns are filled in accordance with 

 instructions given below. One line is used for 

 each current fix. 



14-176 GEK Serial No.— Obtain the GEK 

 serial number from the corresponding line on 

 oceanograpliic log sheet GEK 1. 



14-177 Greenwich Mean Time. — Obtain 

 the Greenwich mean time for the day, month, 

 and hour from the corresponding line on the 

 GEK-1 sheet. 



14-178 Position of Current Fix. — Obtain in 

 the corrected latitude and longitude from the 

 corresponding line on GEK-1 sheet. 



H. O. 607 



