Metreorological and hydrological data

Introduction/Additional information: 

This message allows the distribution of meteorological and hydrological information. Should there be no positional information or time of measurement, this message should not be transmitted. If there is no data available, default value to be transmitted is the highest available binary value for that particular data field. It is to be displayed as ‘not available’
(not 9999 or zero or similar). This message takes 2 slots. Not all the information specified in the tables will be available at all stations. The interval between the broadcasting of this message should not exceed 12 minutes. Attribute of message: broadcast, shore station transmitting, no acknowledgement required.

Registrant: 
IMO Circ. 236
Message number: 
8
DAC: 
1
FI: 
11
State: 
deprecated
Number of slots (max): 
2
Permitted as from: 
16/05/2004
Not to be used after: 
01/01/2013
Details: 

 

 Parameter    No. of bits    Description  
 Message ID   6  Identifier for Message 8 ; Always 8
 Repeat Indicator   2  Used by the repeater to indicate how many times a message has been repeated.  
 Source ID   30  MMSI number of source station  
 Spare   2  Not used. Should be set to zero.  
 IAI   16  DAC = 001
FI = 11
 Latitude   24  Measuring position, 0 to + /- 90 degrees, 1/1000th minute  
 Longitude   25  Measuring position, 0 to + /- 180 degrees, 1/1000th minute  
 Date and time   16  Time of transmission, Day, hour, minute, (ddhhmm in UTC)  
 Average wind speed   7  Average of wind speed values for the last 10 minutes. 0-120 kts, 1 kt  
 Wind gust   7  Wind gust is the maximum wind speed value reading during the last 10 minutes, 0 - 120 kts, 1 kt  
 Wind direction   9  0 - 359 degrees ,1 degree  
 Wind gust direction   9  0 . 359 degrees, 1 degree  
 Air temperature   11  Dry bulb temperature - 60,0 to + 60,0 degrees Celsius 0,1 of a degree  
 Relative humidity   7  0 . 100%, 1%  
 Dew point   10  - 20,0 - + 50,0 degrees, 0,1 degree  
 Air pressure   9  800 . 1200 hPa, 1 hPa  
 Air pressure tendency   2  0 = steady, 1 = decreasing, 2 = increasing  
 Horizontal visibility   8  0,0 . 25,0 NM, 0,1 NM  
 Water level (incl. tide)   9  Deviation from local chart datum, . .10,0 to + 30,0 m 0,1 m  
 Water level trend   2  0 = steady, 1 = decreasing, 2 = increasing  
 Surface current speed (incl. tide)   8  0,0 . 25,0 kts 0,1 kt  
 Surface current direction   9  0 . 359 degrees, 1 degree  
 Current speed, #2   8  Current measured at a chosen level below the sea surface, 0,0 . 25,0 kts, 0,1 kt  
 Current direction, #2   9  0 . 359 degrees, 1 degree  
 Current measuring level, #2   5  Measuring level in m below sea surface , . 0 .30 m 1 m  
 Current speed, #3   8  0,0 . 25,0 knots, 0,1 knot  
 Current direction, #3   9  0 . 359 degrees, 1 degree  
 Current measuring level, #3   5  Measuring level in m below sea surface, 0 . 30 m 1 m  
 Significant wave height   8  0,0 . 25,0 m, 0,1 m  
 Wave period   6  Period in seconds, 0 . 60 s, 1 s  
 Wave direction   9  0 . 359 degrees, 1 degree  
 Swell height   8  0,0 . 25,0 m, 0,1 m  
 Swell period   6  Period in seconds, 0 . 60 s, 1 s  
 Swell direction   9  0 . 359 degrees, 1 degree  
 Sea state   4  According to Beaufort scale (manual input?), 0 to 12, 1  
 Water temperature   10  -10,0 - + 50,0 degrees, 0,1 degree  
 Precipitation (type)   3  According to WMO  
 Salinity   9  0,0 . 50,0 ., 0,1.  
 Ice   2  Yes/No  
 Spare   6   
 Total Number of bits   352  Occupies 2 slots