AIS message type
AIS message type 19: Extended Class B equipment position report
A type 18 plus name, ship type and dimensions in one two-slot message. What type 19 carries, who sends it, how often, and how to read it.
What type 19 is
Type 19 is a position report that also carries the vessel name, ship and cargo type, dimensions and position-fixing device. It was defined for early Class B equipment, and it takes two slots.
How to read it
Current Class B transponders send their static data as type 24 instead, so type 19 is uncommon in a modern feed.
Field layout
Bit offsets are counted from zero at the first bit of the decoded payload.
| Bits | Field | Notes |
|---|---|---|
| 0–5 | Message type | |
| 6–7 | Repeat indicator | 0 = original, 1 to 3 = repeated by a repeater; 3 means do not repeat |
| 8–37 | MMSI | |
| 46–55 | Speed over ground | 1023 = not available |
| 56 | Position accuracy | |
| 57–84 | Longitude | |
| 85–111 | Latitude | |
| 112–123 | Course over ground | |
| 124–132 | True heading | |
| 133–138 | UTC second | |
| 143–262 | Vessel name | 20 six-bit characters |
| 263–270 | Ship and cargo type | |
| 271–279 | Dimension to bow | |
| 280–288 | Dimension to stern | |
| 289–294 | Dimension to port | |
| 295–300 | Dimension to starboard |
Paste a real sentence into the AIS message decoder to see these fields filled in.
All message types
| Type | Name |
|---|---|
| 1 | Position report, scheduled (Class A) |
| 2 | Position report, assigned schedule (Class A) |
| 3 | Position report, response to interrogation (Class A) |
| 4 | Base station report |
| 5 | Static and voyage related data (Class A) |
| 6 | Binary addressed message |
| 7 | Binary acknowledge |
| 8 | Binary broadcast message |
| 9 | Standard SAR aircraft position report |
| 10 | UTC and date inquiry |
| 11 | UTC and date response |
| 12 | Addressed safety related message |
| 13 | Safety related acknowledgement |
| 14 | Safety related broadcast message |
| 15 | Interrogation |
| 16 | Assignment mode command |
| 17 | DGNSS broadcast binary message |
| 18 | Standard Class B equipment position report |
| 19 | Extended Class B equipment position report |
| 20 | Data link management message |
| 21 | Aid-to-navigation report |
| 22 | Channel management |
| 23 | Group assignment command |
| 24 | Static data report (Class B) |
| 25 | Single slot binary message |
| 26 | Multiple slot binary message with communications state |
| 27 | Long-range AIS broadcast message |