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
IxIxIxXRXR. The code figure IXIXIx 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 XRXR 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
The code group znznTnTnTn is used to report each
depth/temperature group selected as significant
(zOzOTOTOTO indicates surface data). The znzn 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 TnTnTn 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
depthencoded 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
The same data in English units would be encoded as
JJYY 14027 12549 14224 15239 32617 40280 88888 00102
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
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 1ZdZdZdZd 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 k5DcDcVcVc. 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 DcDc in hundreds
and tens of degrees True. Drift is the speed of the
current, which is reported in VcVc, 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.
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
Ocean station platforms and
certain buoys report their assigned block and station
number following a 99999 identifier group.