What is LRIT or Long Range Identification and Tracking System ?

Written by Amit Sharma

The Long Range Identification and Tracking (LRIT) system is a designated International Maritime Organization (IMO) system designed to collect and disseminate vessel position information received from IMO member States ships that are subject to the International Convention for the Safety of Life at Sea (SOLAS).

LRIT is a maritime domain awareness (MDA) initiative to enhance maritime Safety, Security and protect the marine environment. LRIT allows Member States to receive position reports from vessels operating under their flag, vessels seeking entry to a ort within their territory, or vessels operating in proximity to the State’s coastline.

LRIT is a collection and distribution system for basic information on vessels.
There are two aspects to LRIT:

  1. The ‘reporting’ aspect where vessels to which LRIT applies report their identity and position, with a date/time stamp, every six hours (four times per day).
  2. The ‘receiving’ aspect where coastal States can purchase reports when vessels are within 1,000 nautical miles, or where port States can purchase reports when vessels seek entry to a port at a pre-determined distance or time from that port (up to 96 hours pre-entry).

The LRIT system consists of the shipborne LRIT information transmitting equipment, the Communication Service Provider(s), the Application Service Provider(s), the LRIT Data Centre(s), including any related Vessel Monitoring System(s), the LRIT Data Distribution Plan and the International LRIT Data Exchange. 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.

 As per SOLAS Chapter V, Regulation 19-1, on Long Range Identification and Tracking (LRIT) refers to the requirement for specified Convention vessels to automatically transmit their identity, position and date/time of the position at 6-hourly intervals, with an ability to increase the rate to intervals of up to once every 15 minutes when requested.  In addition, the equipment must be able to respond to poll requests.

LRIT users include the following:

  • Flag States may request information on the location of their vessels around the world
  • Coastal States may request information on ships up to 1 000 nautical miles from their coasts irrespective of their flag
  • Port States may request information on those ships that have declared one of their ports as destination, irrespective of their location or flag
  • Search and rescue authorities. 
How does LRIT work?

LRIT Shipborne equipment transmits position information to the Communication Service Provider (CSP).

  • Communication Service Providers (CSP) provide the communication infrastructure and services to ensure the end-to-end secure transfer of the LRIT message between the ship and ASP.
  • Application Service Providers (ASP) provide a communication protocol interface and add information to the LRIT message between the CSP and the LRIT Data Centre.
  • LRIT Data Centre collects and provides LRIT information to its users according to the Data Distribution Plan.

LRIT Data Distribution Plan (DDP) defines rules and access rights (i.e. which users can receive what LRIT information). The DDP server is managed by IMO and is populated by SOLAS Contracting Governments, following IMO technical specifications. International LRIT Data Exchange (IDE) routes LRIT information between LRIT Data Centres according to the DDP.


The LRIT regulation will apply to:

To the following ship types engaged on international voyages.

  1. All passenger ships including high speed craft.
  2. Cargo ships, including high speed craft of 300 GRT and above.
  3. Mobile offshore drilling units

Ships must automatically repost their position to their flag administration at least 4 times a day.

Testing Of  LRIT :

Upon installation the LRIT equipment should be tested by the CSP/ASP in accordance with the LRIT requirements. Ship owners are requested to contact the CSP for testing of sitcom ‘C’ equipment for LRIT with following details.

  1. Name of vessel and call sign.
  2. Ship Imm-c ID.
  3. Make, model and equipment serial number.
  4. Port of registry.
  5. IMO number.
  6. MMSI number
  7. GRP
  8. Sec area certified to operate A1, A2, A3 etc.
  9. Due rate of safety radio survey.
  10. Current log in ocean Area IOR/POR etc.
When can an LRIT ship turn off its LRIT equipment?

A ship engaged on an international voyage may switch off its LRIT equipment only when it is permitted by its Flag Administration, in circumstances detailed in SOLAS V/19:

  1. Where international agreements, rules or standards provide for the protection of navigational information (WARSHIPS for example)
  2. In exceptional circumstances and for the shortest duration possible where the operation is considered by the master to compromise the safety or security of the ship.
  3. When a ship is undergoing repairs in dry-dock or in port or is laid up for a long period, the master may temporarily stop the transmission.
What exemptions are there from LRIT reporting? 

A ship is exempt from reporting if it is-

  1. Fitted with an operating automatic identification system (AIS), under 33 CFR 164.46, and operates only within 20 nautical miles of the United States baseline;
  2. A warship, naval auxiliaries or other ship owned or operated by a SOLAS Contracting Government and used only on Government non-commercial service, or
  3. A ship solely navigating the Great Lakes of North America and their connecting and tributary waters as far east as the lower exit of the St. Lambert Lock at Montreal in the Province of Quebec, Canada.
What can LRIT information be used for? 

LRIT information can only be used for Security, Safety and Environmental protection. The US does recognize the commercial confidentiality and sensitivity of LRIT information and will not be sharing this in any way with commercial entities.


About the author

Amit Sharma

Graduated from M.E.R.I. Mumbai (Mumbai University), After a brief sailing founded this website with the idea to bring the maritime education online which must be free and available for all at all times and to find basic solutions that are of extreme importance to a seafarer by our innovative ideas.

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