AIS (ship positions)
Automatic position beacons that ships send so others can see them.
ModeAIS
FamilyMaritime data
Audio exampleComing
What does it sound like?
Plate 02Maritime data
Short, harsh data bursts.
Field marks161.975 and 162.025 MHz9,600 bits per secondShort bursts from ships and buoys
Who uses it?
Commercial ships and many recreational boats.
Where and when can I hear it?
161.975 and 162.025 MHz.
What do the decoded parts mean?
- MMSI: The ship's nine-digit radio identity.
- Position, speed, course: Where the ship is and where it's heading.
- Name and type: Sent in separate messages from time to time.
Easily confused with
- Digital Selective Calling (DSC): DSC is slower, on marine calling channels