Updated: 26 October 2026 · 3 min read
S-100 is the IHO Universal Hydrographic Data Model – a common language for all navigation data (charts, bathymetry, tides, AtoN, VTS information) so it can be layered on next-generation ECDIS.
Who owns which products?
| Range | Responsible body | Examples |
|---|---|---|
| S-1xx | IHO | S-101 ENC, S-102 bathymetric surface, S-104 water level, S-111 surface currents, S-124 navigational warnings |
| S-2xx | IALA | S-201 AtoN information, S-211 port call message, S-212 VTS digital information service, S-230 application specific messages |
| S-4xx | Other organisations (WMO, IEC…) | S-411 sea ice, S-412 weather overlay, S-421 route plan |
S-201 – Aids to Navigation Information
S-201 is IALA’s product specification for exchanging AtoN information between authorities – AtoN services, hydrographic offices, VTS and service providers. A record can describe physical characteristics (type, shape, colour, topmark), light characteristics (colour, rhythm, period, range, sectors), associated equipment (AIS AtoN, racon, power), position and history, status and management data. Data for display on ships is packaged in the corresponding navigation products (such as S-125) for ECDIS.
S-100 ECDIS timeline
Under IMO’s revised ECDIS performance standards, S-100 ECDIS may be used from 1 January 2026 and is required for new installations from 1 January 2029, with dual S-57/S-100 capability during the transition.
Getting started
- Consolidate your AtoN inventory into a proper database.
- Map existing fields to the S-201 model.
- Assign a unique identifier (MRN) to each AtoN.
- Feed real-time status from remote monitoring into AtoN records.
- Train staff through IALA courses on S-201 data production.
Phuc Nguyen Marine’s monitoring platform stores AtoN data in a structure ready for S-201 conversion. Explore the solution.
References: IHO S-100; IALA S-201 Product Specification; IMO revised ECDIS performance standards; iala.int.