Published on Australian Maritime Safety Authority (

Automatic identification systems on offshore structures

We are responsible for ensuring there is a consistent approach to the use of AIS on offshore structures and facilities. Find out what we will ask you when you apply.

We are the current holder of an Australia wide maritime coast licence for the automatic identification systems (AIS) frequencies 161.975 MHz (AIS1) and 162.025 MHz (AIS2) in the VHF maritime mobile band. The Australian Communications and Media Authority (ACMA) has licensed us to operate a limited coast assigned system subject to the conditions laid down in the relevant maritime coast licence determinations.

We may use our discretion to permit third parties to operate non-shipborne AIS in Australia. As the licence holder, we are bound by the conditions imposed by the Radiocommunications Act 1992. Third parties must also comply with the relevant sections of this Act.

IMO Resolution MSC.140(76) notes that administrations should take steps necessary to ensure the integrity of the radio channels used for AIS in their waters. IMO Resolution MSC.74(69) Annex 3 states that AIS should serve as a means for littoral states to obtain information about ships and be used as a vessel traffic service (VTS) tool. Therefore, it is envisaged that applications for non-shipborne AIS would be limited to state or port authorities.

This document sets out our requirements for AIS deployed on offshore structures and facilities. These include fixed and floating oil and gas production platforms, floating storage facilities, offshore drilling units, large moorings and other potential offshore hazards to navigation.

These guidelines ensure a consistent approach to the use of AIS on offshore structures and facilities in Australia. We require particular information when processing applications to use AIS.


AIS installations on offshore structures and facilities in Australia.


ACMAAustralian Communications and Media Authority
AISAutomatic identification system
COLREGSInternational Regulations for Preventing Collisions at Sea
FATDMAFixed access time division multiple access
FPSOFloating production storage and offloading (vessels).
IALAInternational Association of Marine Aids to Navigation and Lighthouse Authorities
IALA O-139Recommendation O-139 – the marking of man-made offshore structures
IECInternational Electrotechnical Commission
IMOInternational Maritime Organization
ITUInternational Telecommunication Union
MMSIMaritime mobile service identity
MODUMobile offshore drilling unit
VDLVHF data link
VHFVery high frequency


AIS AtoNAn AIS AtoN is a digital aid to navigation (AtoN) promulgated by an authorised service provider using an AIS Message 21 aids to navigation report which can be portrayed on devices or systems (eg electronic chart display and information system (ECDIS), radar or integrated navigation system (INS)).
AIS Base StationThe AIS base station is the most basic AIS related entity of any AIS shore infrastructure. The AIS base station allows for the full control of the AIS VHF data link.
AtoNAid to navigation – a device or system external to vessels that is designed and operated to enhance the safe and efficient navigation of vessels and/or vessel traffic.


AIS can be used on offshore structures and facilities to assist with positive identification by transiting and service vessels. AIS may also be used to assist those operating offshore facilities to monitor vessel traffic in their vicinity including potential and real incursions into exclusion or restricted areas.

Given many AIS transmitters may be used in any one area, a level of control, integrity and protection of the AIS VDL is required in accordance with IMO Resolution MSC.347(91). We monitor the use of the AIS VDL and issue all Australian MMSI numbers, AIS licences and FATDMA time slots to owners of non-shipborne AIS transmitters to ensure there is no interference from co-located services, and provide a level of control to ensure integrity and protection of the AIS VDL.

We will evaluate each application to ensure that the purpose of installation aligns with current, internationally accepted aims and objectives for AIS ashore including IMO, ITU, IALA and IEC guidance.

These requirements have been developed in consultation with Australian ports via the Australian AIS working group, and the Oil and gas security forum (OGSF). They are intended to ensure every installation works correctly and provides reliable service.

General requirements

We will assess each application on its nautical requirement for AIS in support of navigation.

Not all facilities must be marked with AIS, however, where AIS is used to mark an offshore facility it must be marked as an AtoN.

Offshore facilities marked with AIS AtoN will use the appropriate Message 21 coding as contained in the most recent version of Recommendation ITU-R M.1371.

FPSOs and MODUs are considered fixed offshore facilities, however, as they are SOLAS vessels, they should change their AIS navigational status when they connect to a riser or the seabed to indicate moored or at anchor. This status will also apply when using dynamic positioning to conducting undersea operations.

AIS fitted on offshore facilities will be certified to the latest edition of the relevant IEC testing standard (IEC 62320-1 for AIS base stations; IEC 62320-2 for AIS AtoN). On receiving an application, we will liaise with the applicant and ACMA to licence AIS AtoN on offshore structures. We will provide the applicant with MMSI and FATDMA slot allocations for all non-shipborne AIS used on offshore structures and facilities.

To apply for non-shipborne AIS equipment, use AMSA Form 234a for AIS base stations, and AMSA Form 234b for AIS AtoN. Further information is available in the policy for the licensing of non-shipborne AIS units.

Equipment requirements


The AIS AtoN may be an AIS AtoN Type 1, Type 2 or Type 3, as described in IEC 62320-2. The defining dimensions of the offshore structure must be transmitted in accordance with Message 21 as outlined in the most recent version of recommendation ITU-R M.1371. If the AIS AtoN is not within VHF radio range of an existing AIS base station then a new AIS base station should be established within the VHF radio range of the AIS AtoN to ensure the integrity of the FATDMA reservations, and monitoring of the AIS AtoN.

Base station

All AIS AtoN and AIS base stations are to be identified in accordance with the most recent edition of recommendation ITU-R M.585.

Supporting documentation

Last updated: 27 October 2020