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STM Message Formats

Latest offficial STM version of schemas.

Forecast of the future of the standars: Technical-Standard-Forecast

Updated: 2019-05-28

This document describes a method for sharing route data between ships, with an STM compatible system using VDES or AIS equipment for communication.
The Route Message Broadcast is used as a means to indicate intended navigation and route information to nearby ships, allowing ships to avoid ending up in a close quarter situation.
The current and a fixed number of coming route legs of the monitored route is shared with other ships.
The use of this message requires that both the receiving and transmitting ship has AIS standard transponder as well as compatible presentation and navigation systems.

Updated: 2019-03-22

The first route exchange format (RTZ 1.0) was published in Annex (S&T) of the ECDIS test standard IEC61174:2015 in August 2015.

The standard can be purchased at the IEC web shop.

The RTZ format is now updated to version 1.1. In the STM Validation Project we will use RTZ 1.1 with a STM extention.

The STM Project has defined a need of a number of new attributes that not is covered in the Annex S. It was agreed with IEC and CIRM that those attributes can be included as extensions to the standard. An extended version of the standard including those attributes can be found below..

See below for guidelines to the use of RTZ format.

Those of you who have questions or inputs to the guidelines please send them to stm(at)

For testdata please find zipped files below.

If you like to produce your own test data, feel free to use the "RTZ Excel Tool".

Updated: 2019-03-22

The text message is a lightweight message intended to be used in communication between Voyage Information Services implemented in STM. Normally a text message is submitted as a complement in sending voyage plans between different parties in STM.

Updated: 2019-03-22

S124 format is developed for transmission of Navigational Warnings from shore centers to the ships. The current format corresponds to the next aims:  1) to transmit urgent marine safety information to the vessels; 2) to provide full life cycle support of transmitted warning, beginning from its creation to cancellation of this warning.