1. The S-121 Maritime Limits and Boundaries Standard
A Status Report
Liaison from IHO to ISO TC211
November 28th, Wellington, New Zealand
S121PT

2. Purpose
Developed as part of a request from the UN Division for Oceans and Law of the Sea (DOALOS) to enable member States to meet their obligation to depositing their maritime limits and boundaries. 
IHO S-121 describes how to encode and exchange digital maritime limits and boundaries, and the associated juridical zones as described under the United Nations Convention on the Law of the Sea (UNCLOS).  The specification was developed as part of a request from the UN Division for Oceans and Law of the Sea (DOALOS), and enables member States to meet their obligation to depositing their maritime limits and boundaries. 
Under UNCLOS States are able to deposit their Maritime Limits and Boundaries using either charts or lists of coordinates so S-121 requires encodings which can support differing member State requirements using an accessible and comprehensive format. 
As it stands the S121 project team has built a data model that can feed three main use cases
(1)        Support for the deposit of member states Maritime Limits and Boundaries to DOALOS (a human-computer readable format).
(2)        Support for exchange of maritime limits and boundaries data between member states.
(3)        Support for production of charts for use in S-101 and S-57 navigation system. 
The project team in the last year 9 months has consolidated and agreed on the core features of the model. The model was refined following a comprehensive review in May The current version of the model will be exposed for discussion in the upcoming meeting (20th-21st September 2017) to address both the core feature attributes and the remaining part of the standard which provides the integration with ISO This allows for the administration Party, Roles, Rights, Restrictions, Responsibilities associated with Maritime Limits and Boundaries. 
With the recent changes and increased interest in the standard, a website ( was built to raise awareness, improve communications and facilitate access to the current advancements made by the project team. As of September 2017, the team has:  
Built the conceptual model
An example case of an data model implementation
The immediate priorities are to: 
Agree the latest iteration of the model with all stakeholders
Refining the deposit exchange format. More work will have to be done in creating and refining the exchange formats in the next few months
Begin discussions on symbology for all use cases.
Consider metadata and exchange set creation
Start testbed creation with 3rd party software vendors and suppliers.
It is hoped that shortly after the next meeting in December that the standard will reach a significant milestone allowing it to enter a pilot stage. This will be in conjunction with the OGC and will involve participation by industry participants as well as member States in a test bed project.
It is expected that shortly after the meeting in December, that the S121PT will be able to produce further recommendations and submissions to the S100WG.
S121PT

3. Mandate
Support the management and exchange of a State’s Maritime Sovereignty, Sovereign rights extents and associated juridical zones as described under the United Nations Convention on the Law of the Sea (UNCLOS). 
The mandate stems from UN General Assembly resolutions requesting the Secretary-General to improve the existing geographic information system for the deposit by States of charts and geographical coordinates concerning maritime zones, including lines of delimitation in particular by implementing, in co-operation with relevant international organizations technical standards for the collection, storage and dissemination of the information deposited, in order to ensure compatibility among the Geographic Information System, electronic nautical charts and other systems developed by these organizations.
Picture:
S121PT

4. The S-121 MLBs Standard Structure
Based on two levels which follows the basic premise of ISO TC211 of the separation of the “carrier from the content”.
Administer, manage and maintain MLBs
Data Model
Distribute and make MLBs accessible
Exchange formats
Separate the carrier from the content. Where the carrier is the exchange format and the content been the administered information is quite only logical. For example, before producing a financial report, incomes and expenditures are to be gathered and logically organized. Thus before exchanging MLBs, a State administer, manage and maintain the MLBs in some form of data model.
The S-121 data model is by all means not meant to be prescriptive, but instead it aims to be as open as possible. The data model, is really what hold the most information about the MLBs, whereas exchange formats may be only representing a subset of the information found in the data model, a subset extracted and formatted in such a way to fit specific purposes or use cases.
S121PT

5. 50 IHO Members representing:
Participation
50 IHO Members representing:
13 Member States
9 active
6 International Body Members, Liaison and Bodies of Interest
UN-DOALOS, ABLOS, IHB
ISO TC211, INSPIRE
UN-GGIM
6 Observing Industry Members
S121PT

6. WWW.S-121.COM Development Status
Consolidated and agreed on the core features of the model (Dec. 2016).
Discussed core feature attributes and the integration of the ISO19152 standard describing the Party, Roles, Rights, Restrictions, Responsibilities associated with Maritime Limits and Boundaries. (Sept. 2017).
Two member States have shown their interest in using the standard to deposit their limits in the near term. (Sept. 2017).
Presented and published the new communication strategy (Sept. 2017).
The project team in the last year 9 months has consolidated and agreed on the core features of the model. The model was refined following a comprehensive review in May The current version of the model will be exposed for discussion in the upcoming meeting (20th-21st September 2017) to address both the core feature attributes and the remaining part of the standard which provides the integration with ISO This allows for the administration Party, Roles, Rights, Restrictions, Responsibilities associated with Maritime Limits and Boundaries. 
With the recent changes and increased interest in the standard, a website ( was built to raise awareness, improve communications and facilitate access to the current advancements made by the project team. As of September 2017, the team has:  
Built the conceptual model
An example case of an data model implementation
The immediate priorities are to: 
Agree the latest iteration of the model with all stakeholders
Refining the deposit exchange format. More work will have to be done in creating and refining the exchange formats in the next few months
Begin discussions on symbology for all use cases.
Consider metadata and exchange set creation
Start testbed creation with 3rd party software vendors and suppliers.
It is hoped that shortly after the next meeting in December that the standard will reach a significant milestone allowing it to enter a pilot stage. This will be in conjunction with the OGC and will involve participation by industry participants as well as member States in a test bed project.
It is expected that shortly after the meeting in December, that the S121PT will be able to produce further recommendations and submissions to the S100WG.
S121PT

7. Structure of S-121
Based on IHO S-100 (Universal Hydrographic Model) which is based on ISO TC211 suite of standards.
Legal aspects based on ISO LADM
Land Cadaster has essentially one type of feature, the land parcel and makes use of a survey model for geometry.
IHO S-121 makes use of the ISO structure for the legal framework (Rights, Responsibilities, Restrictions and Parties) and adds Feature types and geometry consistent with ISO and (per S-100).
Links: Images

8. High Level Model Links: Images

9. Encoding A text based human readable encoding has been developed.
This allows the data to be presented in a court of law to to the UN for legal deposit under UNCLOS.
The data must be readable without the use of any tools.
Two lawers must be able to read the textual data and come to the same understanding.
Links: Images