Can the Automatic Identification System (AIS) transponders be switched off?


di Avv. Simone Moretti

AIS is a tracking device installed on ships that contributes to the safety of navigation and improves the monitoring of maritime traffic control by coastal States.

AIS operates over two VHF channels and provides relevant data about the ID of the ship, cargo, port of departure and destination, position, route and speed.

Data provided by AIS can be exchanged between ships and VTS stations (ship to shore) and between ships at sea (ship to ship).

Although not required by COLREGs rules, nowadays it has become an indispensable tool for the safety at sea. The legal basis of AIS could be found first in the Montego Bay Convention, which provides that States shall take such measures necessary to ensure safety at sea with regard inter alia to: the use of signals, the maintenance of communications and the prevention of collisions.

Pursuant to SOLAS, chapter V, regulation no. 19 AIS should be installed on board of:

  • ships of 300 gross tonnage and upwards engaged on international voyages;
  • cargo ships of 500 gross tonnage and upwards not engaged on international voyages
  • passenger ships, irrespective of size.

EU Directive 2002/59/CE provides a comprehensive system of rules for the use of AIS, stating the mandatory installation for ship over 300GT, with the exception of naval vessels and recreational crafts under 45 meters. Italy transposed the EU norms into the Legislative Decree no. 196 of the 19th August 2005, which provides the mandatory use of AIS for all the ships calling to Italian ports, during navigation and during the approach to the coast. Some exceptions are provided for small passenger ships under 150GT.

A frequently asked question is whether the AIS system can be switched off during navigation or not.

The above query comes by for instance in relation to the more and more frequent switching-off of AIS by ships that intend to avoid request of assistance by migrants’ ships, as for example off the coasts of Libya.

The answer is quite straightforward: NO, AIS cannot be switched off, save for very few exceptions.

According to IMO guidelines provided by Resolution A.917(22), AIS should always be in operation when ships are underway or at anchor. Only if the master believes that the continual operation of AIS might compromise the safety or security of the ship, the AIS may be switched off. “This might be the case in sea areas where pirates and armed robbers are known to operate. Actions of this nature should always be recorded in the ship’s logbook together with the reason for doing so. The master should however restart the AIS as soon as the source of danger has disappeared”.

Therefore AIS should be always kept on use, in so abiding with the basic principles of the safeguard of life at sea.

Coastal laws and ship flags regulations may provide sanctions for not complying with this rule: under Italian law, for instance, a fine from € 1.033,00 to € 6.197,00 plus € 2,58 per GT could be issued.

It is worth noting that any switch-off of the AIS must be duly reported onto the ship’s logbook, and any false representation on the same can be considered a criminal offence. In this regard, article 1127 of the Italian Code of Navigation provides the imprisonment of the captain from 6 months to 5 years for any (wilful) false statement reported on the logbook.

Not to mention that a ship “going dark” may be an easy target for inspections by Authorities, since all ships carrying out criminal activities have usually their positioning system turned off.

In the light of the above, any switch-off of the AIS system must be:

  • carefully considered by the captain and operated only if the safety of the ship can be compromised by the AIS signal;
  • temporary, that is limited to the time necessary to avoid the threat;
  • duly noted onto the ship logbook, without delay.

Avv. Simone Moretti