DEPTH  AND  TEMPERATURE  DATA The largest part of the bathythermograph message, the  reported  significant  depths  and  temperatures, follows the 8888k₁ indicator group. The last digit of the group,  the  k₁  indicator,  is  the  “digitization”  indicator (WMO  Code  Table  2262).  This  value  is  normally  an "8"  in  bathythermograph  observations  taken  from bathythermograph  recorders,  and  means  the  reported depths are at significant levels. A "7" is reported when the depths/temperatures are reported at standard levels, such as 10, 50, or 100 meters. A recent addition to the BATHY code is the group I_xI_xI_xX_RX_R.  The  code  figure  I_XI_XI_x  is  used  to indicate  the  type  of  BT  probe  used  and  the  fall  rate equation  coefficients  of  the  probe.  This  group  is encoded by using WMO International Code 1770, and is listed in Appendix IV. The code figure X_RX_R is used to   indicate   the   recorder   type   used   to   conduct   the observation and is based on WMO International Code 4770, also listed in Appendix IV. NOTE: Instrument Codes 002, 032, 042, and 052 are not used with SIPPICAN MK2/SSQ-61 (Recorder Code  02)  or  SIPPICAN  AN/BQH-7/MK8  (Recorder Code  04) The code group z_nz_nT_nT_nT_n is used to report each depth/temperature   group   selected   as   significant (z_Oz_OT_OT_OT_O  indicates  surface  data).  The  z_nz_n  is  the tens  and  units  digit  of  the  depth  in  meters,  or  the hundreds and tens digit of the depth in feet if in English units. The T_nT_nT_n is the tens, units, and tenths value of the   temperature   in   degrees   Celsius   (or   degrees Fahrenheit).  Water  temperatures  below  0.0°C  are indicated by adding 5 to the tens digit. A group 999zz is inserted  in  the  code  to  indicate  the  hundreds  value (thousands for English) of the depth for the groups that follow it.  In this case, the zz is the hundreds units of the depth—encoded 01 for 100 meters, 02 for 200 meters, etc., and 15 for 1,500 meters. For example, significant depths   and   temperatures   for   “surface,   -   1.1°C;   10 meters, 2.0°C; 24 meters, 4.5°C; 110 meters. 4.0°C; 150 meters,  4.9°C;  and  340  meters,  4.3°C”  would  be encoded  as  follows: JJYY  14027  1254/  14224  15239  32617  41022  88888  00102 00511 10020 24045 99901 10040 50049 99903 40043. The same data in English units would be encoded as follows: JJYY  14027  12549  14224  15239  32617  40280  88888  00102 00301 03356 07401 36392 49409 99901 11397. If  the  last  depth  and  temperature  reported  is  a bottom  water  temperature,  the  last  depth/temperature group will be preceded by the indicator “00000.” This group  is  not  reported  if  the  probe  stopped  reporting before reaching the bottom. BOTTOM  DEPTH  AND  SURFACE CURRENT Section 3 of the code follows the indicator group 66666 and reports the bottom depth and surface current. These  groups  are  optional  but  should  be  reported  by surface  ships  whenever  the  data  can  be  measured.  If both depth and current are not measured, then the entire section  is  not  reported.  If,  however,  either  one  of  the elements is measured, all three groups beginning with the 66666 indicator should be included in the report, and missing  data  should  be  reported  with  slants.  Do  not report charted depths or currents. Charted depths and charted  currents  are  those  depths  and  currents  reported on hydrographic or navigation charts. The   water   depth   measured   by   a   fathometer   is reported  in  group  1Z_dZ_dZ_dZ_d  to  the  nearest  whole  meter (or foot if the 9 indicator is included in the time group). This group is omitted when group 00000 is included in s e c t i o n    2 . The measured or calculated surface current set and drift  are  reported  in  group  k₅D_cD_cV_cV_c.  The  k₅  is  an indicator for the method used to determine the current (WMO Code 2266). This is normally reported as a 3, meaning  the  current  is  determined  from  navigational location “fixes” 3 to 6 hours apart, or a 4 if the fixes are 6 to 12 hours apart. Set is the direction the surface current is moving toward, and is reported in D_cD_c in hundreds and  tens  of  degrees  True.  Drift  is  the  speed  of  the current, which is reported in V_cV_c, in units and tenths of a  knot.  The  measured  water  depth  and  the  calculated current may be obtained from the Quartermaster of the Watch   (QMOW)   on   the   bridge   or   the   Combat Information Center (CIC). The  66666  indicator  group,  bottom  depth  group, and  the  surface  current  group  are  entered  on  the  log sheet in section III, following the depth and temperature information. See figure 2-11. STATION  IDENTIFIER The last section of the report is the station identifier. All ships report only their International Radio Call Sign (IRCS).  Aircraft  report  their  squadron  designator  or  the abbreviation   “ACFT.” Ocean  station  platforms  and certain  buoys  report  their  assigned  block  and  station number following a 99999 identifier group. 2-16