New charting standards, routeing, and gyros.

The IMO’s sub-Committee on Navigation, Communications, Search & Rescue met this week in London.

S-100

A revolution in maritime charting is inbound, with the S-100 suite of new charting standards, products and overlays scheduled for installation on all ECDIS fitted after 1 January 2029.

S-101 Electronic Navigational Charts will present navigational safety information in a new and enhanced manner to seafarers, when compared to current S-57 protocols. Other standards withing the S-100 suite, such as S-111 Surface Current layer, and S-124 Navigational Warnings layer will automate presentation of this supplementary navigational information within ECDIS systems.

Voluntary fitting of S-100 capable ECDIS commenced on 1 January 2026.  However, it is reported that no S-100 ECDIS are commercially available at present. In consequence, The Nautical Institute raised concerns that no general seafarer training nor fleet-wide experience of S-100 operations is currently being gained.

Of equal concern are the cyber security issues of connecting ECDIS via Internet Protocol to a variety shore servers, including for the S-411 Ice Information, S-412 Weather and Wave Information, and also S-421 Route Exchange (with, for example, VTS services). The sub-Committee heard that the SECOM standard is intended to address such concerns, although this remains under test.

The sub-Committee noted a high-level summary of elements associated with the implementation of S-100 capable ECDIS and agreed two draft Maritime Safety Committee Circulars regarding IP connectivity and digital route exchange.

Performance Standards for Gyro Compasses

A sustained debate was held regarding Assembly Resolution A.424(XI), agreed in 1979, which sets out the performance standards for gyro compasses. Specifically, a proposal was made to update gyro compass standards for latitudes above 60degrees.  Whilst the current standards focus on gyro settling time and heading accuracy in latitudes below 60degrees, many countries noted that no issues have been reported regarding compass performance in high latitudes and were concerned that amendments could have unintended negative consequences.

The sub-Committee decided that a new set of performance standards was an appropriate way to address the gaps identified.

R-Mode

R-Mode is a terrestrial navigation system under development for the maritime domain that provides redundancy in case of a GNSS outage. It enables positioning and timing up to distances of a few hundred kilometres from shore if a sufficient number of R-Mode signals are available from relevant base stations.

Standards for R-Mode performance were further developed by the sub-Committee, alongside a debate to consider if R-Mode should be considered as backup system to the worldwide radio navigation system, as an independent system.  It was accordingly opined that the IMO should confine itself to regulating on what is necessary, not what is available.

In consequence, it was decided that formal IMO inclusion of R-Mode by amendment of relevant resolutions is premature at this stage. Notwithstanding, performance standards for shipborne R-Mode receiver equipment were developed and a draft Maritime Safety Committee circular was agreed for subsequent adoption by MSC 112. 

New Routeing Measures

Minor amendments were agreed to BONIFREP, WETREP and CALDOVREP VTS reporting schemes, whereby under the miscellaneous reporting section information about insurance must be submitted to the relevant authorities. Having been examined and agreed at this sub-Committee, these amendments need to be adopted by the next session of the Maritime Safety Committee (December 2026) prior to coming into force.

Four amendments to traffic separation schemes off the Atlantic Coast of the USA were also agreed (Delaware Bay; off New York; Approaches to Cape Fear River; and approaches to Chesapeake Bay). These will be also forwarded to the Maritime Safety Committee for formal adoption.

Weather Information Survey

The World Meteorological Organization issued a call for mariners to input to a technical survey which will help identify user requirements for observations of ‘geophysical variables’ (i.e. sea level, temperature, wave height and other charting observations).  Members are encouraged to participate at this URL.

Acknowledgements

The Nautical Institute was represented at this IMO sub-Committee by Captains Chris O’Flaherty AFNI, Andre LeGoubin FNI, Jun Galvez AFNI, and Margaret Fitzgerald AFNI plus Gina Kim MNI.