3rd Joint IHO-IALA Workshop
Hosted by IALA, IHO and the Directorate General of Coastal Safety of Türkiye in Istanbul from 1 to 4 September 2026, the 3rd Joint IHO–IALA Workshop on S-100/S-200 Development and Portrayal brought together more than 70 experts from hydrographic offices, Marine Aids to Navigation authorities, maritime administrations, international organisations, industry and academia. Discussions covered standards alignment, operational implementation, secure data exchange, data quality and validation, practical use cases and lessons learned. The workshop confirmed that S-100 and S-200 have entered the operational phase, requiring closer, regular cooperation among IALA, IHO, industry and Member States to deliver interoperable digital maritime services that support safer, more efficient and more sustainable navigation. An annual joint event should be considered to sustain implementation, interoperability, training and shared problem-solving. Future meetings should also consider SOLAS carriage requirements for nautical publications, including the List of Lights. Conclusions of the workshop included:
Operations
- Create and routinely maintain validation procedures for all Product Specifications, including manual-entry controls and data-confidence indicators such as CATZOC, using IHO C-615 and IALA guidance.
- Use the AtoN Maritime Resource Name consistently; align S-201 and S-125 with S-101 without reopening the mature S-101 specification, with future AtoN recommendations coordinated after 2030.
- Agree national S-201 data-exchange workflows between AtoN Authorities and Hydrographic Offices; retain both AIS AtoN portrayals and continue reviewing the List of Lights.
- Advance the IHO-NIPWG description of the relationships among S-101, S-201, S-124 and S-125.
Technical
- Clarify how streaming, real-time and message-based services, including S-210, S-212 and S-421, fit within S-100 and its interoperability provisions.
- Resolve governance between IHO and IALA Maritime Connectivity Platform instances, covering certificates, recognition, revocation, liability and responsibilities; interoperable trust domains may improve resilience.
- Strengthen schema quality assurance and business-rule validation, supported by the IHO Infrastructure Centre, and provide shared production, validation and distribution tools for AtoN authorities, potentially through RENCs or similar bodies.
- Align S-100 Part 14 with IALA Guideline G1128, establish an IHO process for technical service specifications, link IALA Technical Services in the GI Registry, and apply S-258 checks alongside any required national rules.
Training
- Give training greater prominence at future joint workshops, with participation from IHO, IALA, industry and other relevant bodies.
- Improve awareness and accessibility of S-100/S-200 learning, organised at Base, General and Super levels rather than by role.
- Review existing UKHO, PRIMAR and other materials; explore cooperation agreements and educational simulators; promote user benefits and equip senior leaders to support transition.
