AIS, LRIT & BNWAS

Question 1

What is AIS?

Answer 1

Maritime Mobile VHF broadcast system

Question 2

Who needs AIS?

Answer 2

• All ships of 300GT and over, engaged on international voyages
  
  • Cargo Ships of 500 GT and over, not engaged on international voyages
• All Passenger Ships

Question 3

How does AIS work?

Answer 3

AIS transceivers automatically broadcast information, such as position, speed, and navigational status, at regular intervals via a VHF transmitter built into the transceiver.

Question 4

What info does AIS give?

Answer 4

• static (MMSI, Ship’s Name, C/S)
• dynamic (from ships sensors)
• voyage related data (manually entered)

Question 5

Use of AIS for Navigation

Answer 5

AIS provides identification of targets together with the static and dynamic information which assists with situational awareness. However, Collision Avoidance should be made strictly according to the COLREGs.

Question 6

Limitations of AIS

Answer 6

Not all ships are fitted with AIS, it can also be switched off.
Faulty data inputs

Question 7

Virtual AIS

Answer 7

Symbol: ‘open diamond with crosshair centred’
A recent development of AIS is the ability to provide synthetic AIS targets and virtual navigation marks as aids to navigation (AtoN), in addition to the physical AIS AtoNs, enabling coastal authorities to provide an AIS symbol on the display in any position.
This ability could lead to the appearance of “virtual” AIS targets and therefore take particular care when an AIS target is not complemented by a radar target.

Question 8

What is LRIT

Answer 8

Long Range Identification Tracking
system
provides the global identification and tracking of ships
to enhance security of shipping and
for the purposes of
safety and marine environment protection.

info auto-transmitted at 6 hr intervals or remotely at any time.

MGN 634

Question 9

BNWAS, what does it do?

Answer 9

The purpose of a bridge navigational watch alarm system (BNWAS) is to monitor bridge activity and detect operator disability, which could lead to marine accidents.

The system monitors the awareness of the OOW and automatically alerts the Master if for any reason the OOW becomes incapable of performing the OOWs duties.

Additionally, BNWAS may provide the OOW with a means of calling for immediate assistance in bridge if required.