AIS (Automatic Identification System)

Question 1

How does AIS operate?

Answer 1

• Provides a ‘picture’ of the vessel around our ship.
• Operates independently of RADAR.

Question 2

What information does AIS relay?

Answer 2

• Provides Ship Data, such as ships name, type, MMSI, status, cargo, destination, etc.
   LRIT: Long Range Identification and Tracking, uses satellite data and AIS to track vessels worldwide, sent every 6 hours automatically to Flag State.

Question 3

What is Dynamic data?

Answer 3

• Ships position (WGS84).
• Time in UTC.
• COG.
• SOG.
• Heading.
• Navigational status.
• Rate of turn.
• angle of heel.

Question 4

What is Static data?

Answer 4

• IMO Number (MMSI)
• Call sign and name.
• Length and beam.
• Type of ship.
• Location of position-fixing antenna on the ship.

Question 5

What is Voyage data?

Answer 5

• Ships draft.
• Hazardous cargo type.
• Route Plan (Waypoints).
• Destination and ETA.
• Route plan.

Question 6

How often is AIS class-A broadcasted?

Answer 6

Broadcasts dynamic data every 2-12 seconds while underway and every 3 minutes while at anchor.

Question 7

What is class-B?

Answer 7

Class-b operates with smaller transceivers to small vessels all the AIS features of class-A devices, but without some of the requirements needed for larger vessels.

Question 8

What is the difference between and class-A and class-B?

Answer 8

• Class-B has a lesser reporting rate than Class-A.
• Class-B units do not transmit navigational status.
• Class-B units do not transmit IMO numbers or call signs.
• Class-B units do not transmit ETA or destinations.
• Class-B units do not transmit rate of turn information.
• Class-B units do not transmit the maximum present static draught.
• Class-B units are only required to receive safety messages, binary messages.