Navigation of Maritime Border Delimitations through S-121 Development

Navigation of Maritime Border Delimitations through S-121 Development

The International Hydrographic Organization (IHO) has recently released the S-121 Ed 1.0.0 for implementation and testing purposes, marking a significant step towards the digital representation of maritime limits and boundaries according to the United Nations Convention on the Law of the Sea (UNCLOS).

Currently, the IHO S-121 standard is under development and is progressing towards operational use. The organization aims to designate a small number of these standards in 2026, with an expectation of operational deployment by 2027.

The S-121 standard is part of the IHO’s suite of standards for hydrographic data, designed to provide standardized digital encoding for maritime limits and boundaries, including baselines, territorial seas, exclusive economic zones, and other maritime zones defined under UNCLOS. This new standard is expected to improve interoperability and facilitate consistent legal and navigational representation of maritime boundaries in electronic charting and geographic information systems.

While existing standards like IHO S-57, which NOAA's Electronic Navigational Charts (ENC) comply with, and electronic charting systems (ECDIS) integrating navigational data and positional information are widely known, technical implementation details for S-121 remain limited in public documentation. However, the direct information about IHO S-121’s operational timeline and its linkage to UNCLOS definitions comes from an IHO-related projection targeting designation in 2026 and operational status in 2027.

The S-121 data model incorporates the geometry, entity structure, and attributes of the IHO S-100 model and defines new features, attribute types, and relationships. This standard is further developed in the Open Geospatial Consortium (OGC) pilot project on Maritime Limits and Boundaries.

The S-121 standard is intended for the encoding and exchange of digital maritime boundary information as described in the United Nations Convention on the Law of the Sea. To ensure compatibility with electronic nautical charts developed according to the guidelines and standards of the International Hydrographic Organization (IHO), the General Assembly requested the Secretary-General to implement international technical standards for data deposited by coastal States.

Under the terms of the Convention, a copy of these charts or lists of coordinates shall be deposited with the Secretary-General of the United Nations. The IHO S-121 product specification provides information on reference systems and metadata, as well as multiple aspects of the data itself (i.e. product identification, content and structure, quality, capture, product format (encoding), and product delivery).

The IHO S-121 project team, which includes Jean-Francois Beaupre, Serge Leveque, Ryan Ahola, Sebastien Durand, C. Douglas O'Brien, Jonathan Pritchard, and Mark Alcock, developed the standard. C. Douglas O'Brien, the President of IDON Technologies Inc., brings extensive experience with respect to Information Technology with emphasis on the handling of spatial data in a standards environment.

Since the entry into force of the Convention in 1994, implementing coastal States have the responsibility of making public, in the form of charts or lists of geographical coordinates, the position of baselines, outer limits and boundaries used to define their territorial sea, archipelagic baselines used to define their archipelagic waters, outer limits and boundaries used to define their exclusive economic zone, and outer limits and boundaries used to define their continental shelf.

The S-121 standard allows a digital realization of an important international agreement signed by 168 parties (UN DOALOS, 2021). In 2005, the United Nations General Assembly requested the Secretary-General to improve the Geographic Information System (GIS) which supported the system for recording and publicizing charts and lists of geographical coordinates defining the maritime zones of coastal States.

In conclusion, the IHO S-121 standard is a forthcoming digital encoding system for maritime limits and boundaries as defined by UNCLOS. It is scheduled for initial designation in 2026 and expected operational deployment by 2027. It complements existing hydrographic standards (like S-57) used in electronic navigation and charting but focuses specifically on maritime boundaries. Detailed technical implementation specifics are presently limited in public documentation but would encompass integration into electronic chart systems to support maritime jurisdictional clarity.

1. The scientific community anticipates that the operational deployment of the S-121 standard in 2027 could significantly enhance the accuracy and interoperability of medical-conditions data, as it caters specifically to the digital representation of maritime boundaries according to the United Nations Convention on the Law of the Sea (UNCLOS).
2. In the realm of health-and-wellness, the S-121 standard, with its focus on precise maritime spatial data, could potentially aid in monitoring and managing marine ecosystems, providing crucial data for research and conservation efforts in coastal and oceanic regions.

Read also: