IMSO study on full exercise of LRIT coastal State entitlement
The study examines the operational implications for the Long-Range Identification and Tracking of Ships (LRIT) system in the event that all Contracting Governments were to fully exercise their coastal State entitlement under SOLAS regulation V/19-1. It is based on data collected from all 71 Data Centres, covering 135 flag States and a total of 39,517 ships, using 30-day audit samples distributed across the full calendar year. The dataset was reviewed to ensure that it provides a reliable basis for annual estimates, with no indication of seasonal bias affecting the results. This study was initiated as a result of discussions at IMO on the financial architecture of the LRIT system.
Circular Letter
IMSO Circular Letter No. 57 was issued on 27 April 2026. It includes a cover letter providing the rationale for the study, an executive summary and an overview of the study methodology and other key aspects of the study. The full technical report and statistical basis for the study are included as annexes to the document.
You can download a copy of IMSO Circular Letter No. 57 here:
Technical Report
This report presents the findings of an analysis conducted by IMSO to estimate the volume and geographic distribution of LRIT messages that would flow through the International LRIT Data Exchange (IDE) if all Contracting Governments were to exercise, in full, their entitlement to receive LRIT information under SOLAS regulation V/19-1.
You can download a copy of the Technical Report here:
Statistical Basis
This document sets out the statistical validity of the one-month-per-DC sample used to extrapolate LRIT message traffic to annual estimates, and to assess IDE capacity requirements under full coastal State monitoring conditions.
You can download a copy of the Statistical Basis for the study here:
