Message ID

6

Identifier for this Message 5

Repeat indicator

2

Used by the repeater to indicate how many times a message has been repeated. Refer to § 4.6.1, Annex 2; 0-3; 0 = default; 3 = do not repeat any more

User ID

30

MMSI number

AIS version indicator

2

0 = station compliant with Recommendation ITU-R M.1371-1
1 = station compliant with Recommendation ITU-R M.1371-3
2-3 = station compliant with future editions

IMO number

30

1-999999999; 0 = not available = default

Call sign

42

7 = 6 bit ASCII characters, @@@@@@@ = not available = default

Name

120

Maximum 20 characters 6 bit ASCII “@@@@@@@@@@@@@@@@@@@@” = not available = default

Type of ship and cargo type

8

0 = not available or no ship = default
1-99 = as defined below
100-199 = reserved, for regional use
200-255 = reserved, for future use

Overall dimension/
reference for position

30

Reference point for reported position.
Also indicates the dimension of ship (m) (see below)

Type of electronic position fixing device

4

0 = undefined (default)
1 = GPS
2 = GLONASS
3 = combined GPS/GLONASS
4 = Loran-C
5 = Chayka
6 = integrated navigation system
7 = surveyed
8 = Galileo,
9-15 = not used

ETA

20

Estimated time of arrival; MMDDHHMM UTC
Bits 19-16: month; 1-12; 0 = not available = default
Bits 15-11: day; 1-31; 0 = not available = default
Bits 10-6: hour; 0-23; 24 = not available = default
Bits 5-0: minute; 0-59; 60 = not available = default

Maximum present static draught

8

In 1/10 m, 255 = draught 25.5 m or greater, 0 = not available = default; in accordance with IMO Resolution A.851

Destination

120

Maximum 20 characters using 6-bit ASCII;
@@@@@@@@@@@@@@@@@@@@ = not available

DTE

1

Data terminal equipment (DTE) ready (0 = available, 1 = not available = default)

Spare

1

Spare. Not used. Should be set to zero. Reserved for future use.

Number of bits

424

Occupies 2 slots

Identifier No.

Special craft

50

Pilot vessel

51

Search and rescue vessels

52

Tugs

53

Port tenders

54

Vessels with anti-pollution facilities or equipment

55

Law enforcement vessels

56

Spare – for assignments to local vessels

57

Spare – for assignments to local vessels

58

Medical transports (as defined in the 1949 Geneva Conventions and Additional Protocols)

59

Ships according to RR Resolution No. 18 (Mob-83)

Identifiers to be used by ships to report their type

Other ships

First digit(1)

Second digit(1)

First digit(1)

Second digit(1)

1 – Reserved for future use

0 – All ships of this type

–

0 – Fishing

2 – WIG

1 – Carrying DG, HS, or MP, IMO hazard or pollutant category A

–

1 – Towing

3 – See right column

2 – Carrying DG, HS, or MP, IMO hazard or pollutant category B

3 – Vessel

2 – Towing and length of the tow exceeds 200 m or breadth exceeds 25 m

4 – HSC

3 – Carrying DG, HS, or MP, IMO hazard or pollutant category C

–

3 – Engaged in dredging or underwater operations

5 – See above

4 – Carrying DG, HS, or MP, IMO hazard or pollutant category D

–

4 – Engaged in diving operations

5 – Reserved for future use

–

5 – Engaged in military operations

6 – Passenger ships

6 – Reserved for future use

–

6 – Sailing

7 – Cargo ships

7 – Reserved for future use

–

7 – Pleasure craft

8 – Tanker(s)

8 – Reserved for future use

–

8 – Reserved for future use

9 – Other types of ship

9 – No additional information

–

9 – Reserved for future use

(1)      The identifier should be constructed by selecting the appropriate first and second digits.