Long-range identification and tracking (LRIT)

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

The obligations of ships to transmit LRIT information and the rights and obligations of SOLAS Contracting Governments and of Search and rescue services to receive LRIT information are established in regulation V/19-1 of the 1974 SOLAS Convention.

The LRIT system consists of:

  • the shipborne LRIT information transmitting equipment; 
  • the Communication Service Provider(s) (CPS); 
  • the Application Service Provider(s) (ASP); 
  • the LRIT Data Centre(s) (DC), including any related Vessel Monitoring System(s) (VMS); 
  • the LRIT Data Distribution Plan (DDP); and 
  • the International LRIT Data Exchange (IDE). 

Certain aspects of the performance of the LRIT system are reviewed or audited by the LRIT Coordinator acting on behalf of all SOLAS Contracting Governments.

LRIT information is provided to Contracting Governments to the 1974 SOLAS Convention and Search and rescue services entitled to receive the information, upon request, through a system of National, Regional and Cooperative LRIT Data Centres using the International LRIT Data Exchange.

Each Administration should provide to the LRIT Data Centre it has selected, a list of the ships entitled to fly its flag, which are required to transmit LRIT information, together with other salient details and should update, without undue delay, such lists as and when changes occur. 

Ships should only transmit the LRIT information to the LRIT Data Centre selected by their Administration.

LRIT system operation

Tracking of any applicable ship begins with LRIT information being transmitted from the shipborne equipment. 

The LRIT information transmitted includes the ship's GNSS position (based on the WGS 84 datum), time and identification of the shipborne equipment. The shipborne equipment should be set to automatically transmit the ship's LRIT information at 6-hour intervals to the DC identified by the flag Administration, unless the Contracting Government requesting the provision of LRIT information specifies a more frequent transmission interval.

The LRIT information transmitted from the ship travels across the communication path set up by the CSP to the ASP. The ASP, after receiving the LRIT information from the ship, adds additional information to the LRIT message and passes the expanded message to its associated DC. DCs should store all incoming LRIT information from ships instructed by their Administrations to transmit LRIT information to that DC. DCs disseminate LRIT information to LRIT Data Users according to the DDP which contains the information required by the DCs for determining how LRIT information is distributed to the various Contracting Governments.

The IDE processes all LRIT messages between DCs and routes them to the appropriate DC based upon the address in the message. The IDE neither processes nor stores the information contained within LRIT messages.

LRIT Data Users  might be entitled to receive or request LRIT information in their capacity as a flag State, port State, coastal State or Search and Rescue service as prescribed in regulation V/19-1 of the 1974 SOLAS Convention.

The LRIT Coordinator assists in the establishment of components of the LRIT system (namely the IDE and IDC), performs administrative functions, and reviews and audits the performance of certain components of the LRIT system.

Related Documents

Title Date

LRIT Technical documentation (Part I)


LRIT Technical documentation (Part II)


Guidance in relation to certain types of ships which are required to transmit LRIT information, on exemptions and equivalents and on certain operation matters


Guidance on the implementation of the LRIT system


Guidance on the survey and certification of compliance of ships with the requirement to transmit LRIT information


Guidance to search and rescue services in relation to requesting and receiving LRIT information


Continuity of service plan for the LRIT system


Principles and guidelines relating to the review and audit of the performance of LRIT Data Centres and the International LRIT Data Exchange

MSC 86/INF.16

LRIT Data Distribution Plan - Accessing and entering information Guidance notes for Contracting Governments Developmental and integration testing Guidance notes for LRIT Data Centres

Resolution MSC.202(81)

2006 SOLAS (chapter V) amendments

Resolution MSC.211(81)

Arrangements for the timely establishment of the Long range identification and tracking system

Resolution MSC.242(83)

Use of Long-range identification and tracking information for safety and marine environmental protection purposes

Resolution MSC.263(84)/Rev.1

Performance standards and functional requirements for the long-range identification and tracking of ships

Resolution MSC.264(84)

Establishment of the International LRIT Data Exchange on an interim basis

Resolution MSC.275(85)

Appointment of the LRIT Coordinator

Resolution MSC.276(85)

Operation of the International LRIT Data Exchange on an interim basis

Resolution MSC.297(87)

Establishment of the International LRIT Data Exchange

Resolution MSC.298(87)

Establishment of a distribution facility for the provision of LRIT information to security forces operating in waters of the Gulf of Aden and the western Indian Ocean

Resolution MSC.322(89)

Operation of the International LRIT Data Exchange

Resolution MSC.331(90)

Adoption of amendments to Resolution MSC.298(87) on Establishment of a distribution facility

Resolution MSC.361(92)

Operation of the International LRIT Data Exchange after 2013

Authorized testing ASPs