West of England P&I Club’s Emma Forbes-Gearey, Loss Prevention Officer, provides three practical steps to promote better Automatic Identification System (AIS) use.
AIS, also known as the Automatic Identification System, was initially a standalone unit for reference for watchkeeping officers. Most vessels have integrated bridge systems and can overlay AIS data onto radar screens. However, the Club reports it has recently seen several AIS-assisted collisions and advises that solely using the AIS for collision avoidance purposes must never be undertaken by the bridge team.
Guidance regarding the use of AIS
- Ensure you understand what information radar displays, what the AIS can provide, and what information it cannot. The equipment cannot tell you that there is no risk of collision.
- Use all aids to navigation. Do not solely rely upon one aid. Therefore, in combination with the radar, obtain visual bearings and compare them against all other means to ascertain whether a risk of collision exists. If in doubt as to whether a risk of collision exists, then the actions taken must be under the COLREGS, especially Rule 7.
- Standardise how you set up the equipment and understand the source of your information, especially if there are multiple sources, notably with integrated bridge systems and the use of overlays, whether this is AIS on the Radar or Radar overlays on the ECDIS. Individual manufacturers produce different displays; therefore, understand your equipment as the officer of the watch’s responsibility is to ensure the safe and smooth navigation of the ship.
When navigating, watching-keeping officers must adhere to the COLREGS, also known as “Rules of the Road”. However, these rules do not specify the role of AIS and other navigational aids, other than in Rule 5, ‘keeping a proper lookout’, which stipulates the use of ‘all available means’.
Nonetheless, Rule 7 concerning the risk of collision shall be complied with:
(a) Every vessel shall use all available means appropriate to the prevailing circumstances and conditions to
determine if risk of collision exists. If there is any doubt such risk shall be deemed to exist.
(b) Proper use shall be made of radar equipment if fitted and operational, including long-range scanning to
obtain early warning of risk of collision and radar plotting or equivalent systematic observation of detected
objects.
(c) Assumptions shall not be made on the basis of scanty information, especially scanty radar information.
(d) In determining if risk of collision exists the following considerations shall be among those taken into
account:
(i) Such risk shall be deemed to exist if the compass bearing of an approaching vessel does not
appreciably change;
(ii) such risk may sometimes exist even when an appreciable bearing change is evident, particular
IMO Guidance and Limitations
AIS can be used with discretion and in combination with other equipment. It shall not be used solely for collision avoidance. Cross-checking is required because there can be a high risk of inaccuracies in the information it displays. Unlike other data sources that can be obtained visually or by the radar, the information that goes into the AIS depends on other equipment and user input. Therefore, the validity of the AIS information received is only as good as the accuracy of the information transmitted. The IMO has produced guidance regarding the use of AIS, found in Resolution A.1106(29).
