Binary AIS Message Decoding Status

There is a massive amount of confusion in the detailed specification of binary messages, in particular with the international messages.
It appears too many international bodies have had their finger in the pie and failed to agree even on the basics.
In particular the ITU, IMO(SN/Circ 236) and IALA have released contradictory and inconsistent specifications. The IMO appear to have been given the job of sorting it out. For Example, data fields are too small to hold the data specified, data format not specified, data field sizes do not add up to total record size. The equipment manufacturers must be pulling their hair out.
This is causing me big difficulties decoding the data, not least because what is actually being transmitted (where I have seen it) differs!
IMO SN239 has clarified some issues.

International Messages (DAC=1)
All the "new" (FI=18-32) messages have now been decoded (excepting 21-1).
Where I have seen the "old" messages, I have decoded them. Where there are conflicting specifications, the message size is used to decided which type of message it actually is.
 
Inland Waterways (DAC=200)
These now appear to be the responsibility of the United Nations - the specification appears to be consistent and has been adopted by Europe through various EU bodies and by CCNR (Central Commission for Navigation on the Rhine). So far I have only actually seen is the Extended Vessel/voyage details, which is being used by barges in Europe. As the EU are giving grants to encourage further use, I expect this will gain momentum.

St Lawrence Seaway (DAC=366/316, FI 1,2,32)
All messages have been decoded using the V4.0A specification. Although the specification is clear, it appears some messages being transmitted are not in agreement with the specification for example the default wind speed appears incorrect (101.4 cf 102.3)). As I do not have samples of some Message ID's, not all have been verified. Apart from some of the environmental messages, the only Lockage message I have seen is the Lockage Order message.

USA (DAC=366)
All the environmental messages (FI=33) have been decoded - not all have been verified

UK & ROI (DAC=235/250)
The AtoN status message (FI=10) has been decoded and is being used by Trinity House, Northern Lights and the Commissioners of Irish Lights to remotely monitor the status of buoys.

Denmark (DAC 219)
FI (1,2 & 3) are awaiting decoding.

Other Messages
Some other messages have been decoded, by making an educated guess.

Examples
If there is no example, it's because I have yet to receive the message.

Status
DAC
FI Source or ID Description Status
0
 Test only Any
Is incorrectly used by some shore stations and responded to by some vessels.
1 International 0 ITU Text Telegram AIS Binary Message, DAC=1, FI=0 Decoded


1
 ITU
 Application acknowledgement AIS Binary Message, DAC=1, FI=1 Replaced by 5


2 ITU Interrogation on specific IFM AIS Binary Message, DAC=1, FI=2 Decoded


3 ITU Capability interrogation AIS Binary Message, DAC=1, FI=3 Decoded


4 ITU Capability interrogation reply AIS Binary Message, DAC=1, FI=4 Decoded


5
 ITU
 Application acknowledgement to an addressed binary message
Decoded


11


 IMO/236
IALA/2004
 Meteorological and Hydrological data not to be used after 1 Jan 2013 AIS Binary Message, DAC=1, FI=11 Decoded


12

 IMO/236
IALA/2004
 Dangerous Cargo Indication not to be used after 1 Jan 2013 Replaced by 25


13

 IMO/236
IALA/2004
 Fairway closed not to be used after 1 Jan 2013 Replaced by 22


14


 IMO/236
IALA/2004
 Tidal Window  not to be used after 1 Jan 2013 (USCG)
(IMO to hour/min fields missing)		 Decoded


15

 IMO/236
IALA/2004
 Extended static and voyage related data [Air draught only] not to be used after 1 Jan 2013
Decoded


16


 IMO/236
IALA/2004
IMO/289
 Number of persons on board - conflicts with below
IMO/289 corrected


 		Decoded


16

 IALA/2002

 VTS Targets - Legacy is used by some shore stations 2014)
AIS Binary Message, DAC=1, FI=16 		Decoded


17


 IMO/236
IALA/2004
IMO/289
 Pseudo-AIS Targets renamed VTS-generated/synthetic targets


 		Decoded


17
 IALA/2002
 Ship Waypoints and/or Route Plan report - now disused (IMO 2006)
 disused


18
 IALA/2002
 Advice of waypoints and/or route plan of VTS - now disused (IMO 2006)
 disused


18
 IMO/289
 Clearance time to enter port (IMO total incorrect, destination added IMO/289)
 Decoded


19
 IALA/2002
 Extended static and voyage related data [Air draught only] (IALA) AIS Binary Message, DAC=1, FI=19
 Decoded


19
 IMO/289
 Marine Traffic Signal (IMO signal format not specified, specified in IMO/289)
 Decoded


20
 IMO/2009
 Berthing Data
 Decoded


21
 IMO/2009

 Weather Report from Ships (IMO hPa field size incorrect)
Replaced by 21:0,21:1


21
 0
IMO/289		 Weather Report from Ships Decoded



1
IMO/289
 WMO Weather Report from Ships Awaiting Decoding


22
 IMO/289
 Area Notice - broadcast AIS Binary Message, DAC=1, FI=22 Decoded


23
 IMO/289
 Area Notice - addressed
 Decoded


24
 IMO/289
 Extended static and voyage related data - Broadcast
 Decoded


25
 IMO/289
 Dangerous Cargo Indication - addressed
 Decoded


26
 IMO/289
 Environmental - (IMO most copied from [366-33] including errors !, check IMO/289)
 Decoded


27
 IMO/289
 Route Information - broadcast AIS Binary Message, DAC=1, FI=27 Decoded


28
 IMO/289
 Route Information - addressed  (IMO spec says 27, corrected IMO/289) AIS Binary Message, DAC=1, FI=28 Decoded


29
 IMO/289
 Text Description - broadcast
 Decoded


30
 IMO/289
 Text Description - addressed AIS Binary Message, DAC=1, FI=30 Decoded


31
 USCG/2009
IMO/289
 Met/Hydrographic - broadcast AIS Binary Message, DAC=1, FI=31 Decoded


32
 USCG/2009
IMO/289
 Tidal Window - addressed
 Decoded


40


 IALA/2002


 Number of Persons on board - is used by 002655651 (Sweden shore station & is responded to by Swedish Vessels [MID 256]) also used by UK 002320706 [North Foreland] & responded to by UK vessels AIS Binary Message, DAC=1, FI=40 Decoded
200 Inland Waterways 8

 Assumpted

 Inland ship static and voyage related data - appears to be an old format AIS Binary Message, DAC=200, FI=8 Decoded


10
 UN
 Inland ship static and voyage related data AIS Binary Message, DAC=200, FI=10 Decoded


21
ETA at lock/bridge/terminal
 Decoded


22
RTA at lock/bridge/terminal
 Decoded


23
EMMA warning
 Decoded


24
Water level
 Decoded


40
Signal status
 Decoded


55
Inland number of persons on boardAIS Binary Message, DAC=200, FI=55
 Decoded
210
 Cyprus
 0
Text Telegram AIS Binary Message, DAC=210, FI=0 Decoded
219
 Denmark
 1
Intended Route
 Awaiting Decoding


2
Route suggestion
 Awaiting Decoding


3
Route suggestion reply
 Awaiting Decoding
232
 UK
 1
Used by ferries within Port of London Authority (PLA)
235/250
 UK/ROI
 10
AtoN Status AIS Binary Message, DAC=235, FI=10 Decoded
248
 Malta
 0
Text Telegram AIS Binary Message, DAC=248, FI=0 Decoded
316/366
 Canada/USA
 1
 USDoT
 Metrological and Hydrological
 Decoded



1
 Weather station messageAIS Binary Message, DAC=316, FI=1, ID=1 Decoded



2
 Wind Information message AIS Binary Message, DAC=316, FI=1, ID=2 Decoded



3
 Water level message AIS Binary Message, DAC=316, FI=1, ID=3 Decoded



4
 PAWSS Hydro/Current
 Decoded



5
 PAWSS Hydro/salinity Temp
 Decoded



6
 Water Flow message AIS Binary Message, DAC=316, FI=1, ID=6 Decoded


2
Vessel/Lock Scheduling
 Decoded



1
 Lockage Order AIS Binary Message, DAC=316, FI=2, ID=1 Decoded



2
 Estimated Lock Times AIS Binary Message, DAC=316, FI=2, ID=2 Decoded



3
 Vessel Procession Order
 Decoded


32
St Lawrence Seaway specific
 Decoded



1
 Message Specification Version AIS Binary Message, DAC=366, FI=32, ID=1 Decoded
353
 Panama
 0
Text Telegram
 Decoded
366
 USA
 22
Area Notice USCG
 Awaiting Decoding


33
Environmental USCG Decoded



0
 Site LocationAIS Binary Message, DAC=366, FI=33, ID=0 Decoded



1
 Station ID AIS Binary Message, DAC=366, FI=33, ID=1 Decoded



2
 Wind AIS Binary Message, DAC=366, FI=33, ID=2 Decoded



3
 Water Level AIS Binary Message, DAC=366, FI=33, ID=3 Decoded



4
 Current Flow 2D (x,y)
 Decoded



5
 Current Flow 3D (x,y,z)  (up vector size incorrect)
 Decoded



6
 Horizontal Current Flow
 Decoded



7
 Sea State
 Decoded



8
 Salinity (record size incorrect)
 Decoded



9
 Weather AIS Binary Message, DAC=366, FI=33, ID=9 Decoded



10
 Air Gap / Air Draft
 Decoded


35
Waterways Management USCG
 Awaiting Decoding


55
USCG - Encrypted Text Message


56
USCG - Encrypted Position Report


57
USCG - Encrypted Static Data


58
USCG - Encrypted Target of Interest


63
Water level



1
 Timed Circular notice



2
 Whale notice