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Updated on 16/05/2024

The national maritime boundaries portal is based on Article 16 of Order No. 2016-1687 of 8 December 2016, with the aim of consulting and disseminating the official elements used to delimit maritime areas under the sovereignty or jurisdiction of the French Republic, in particular legal references and digital data.

Order n° 2016-1687 of 8 December 2016

Decree No. 2017-821 of 5 May 2017 entrusted its design and implementation to Shom, the national hydrographic service.
The portal was inaugurated in June 2018 as the portal for official information on France's maritime delimitations in application of the United Nations Convention on the Law of the Sea, known as the Montenegro Bay Convention.
A steering committee chaired by the General Secretariat for the Sea (SGMer) with representatives from the Ministries of Europe and Foreign Affairs (MEAE), the Armed Forces (MINARM), Overseas France (MOM), and Ecological Transition (MTE), the Directorate General for Maritime Affairs, Fisheries and Aquaculture (DGAMPA) and the Shom set the guidelines for the portal.
Since 2019, in accordance with the guidelines of the steering committee, the portal has been enriched with new regulatory data not governed by the Montégo Bay Convention, for example: boundaries relating to fishing zones, archaeological fees, traffic separation schemes, etc. The scope of the national maritime boundaries portal has therefore been extended beyond the initial theme of maritime delimitations with the addition of four themes (traffic & navigation, occupation & use of the maritime domain, environment, jurisdiction & reporting on the maritime domain).

Decree No. 2017-821 of 5 May 2017

The version of the portal to be launched in February 2023 will be based on five main themes as follows:

  • French maritime areas: to support the initial ambition set by measure no. 77 of the Interministerial Committee for the Sea of 15 November 2018, which makes the portal the reference medium for State communication on maritime delimitations
  • Traffic and navigation: to gather information on the geographical data relating to the limits and surfaces that regulate maritime traffic and navigation (e.g. traffic separation devices, anchorage areas, etc.). 
  • Maritime domain uses: to collect information on the geographical data related to the administrative boundaries and surfaces that regulate the use of the maritime domain and the various activities at sea (e.g. fishing boundaries, boundaries for archaeological research at sea, areas for the implementation of wind turbines or aggregate extraction, various AOTs, etc.) .
  • Environmental protection: to provide information on geographical data related to the protection of the maritime environment (e.g. marine protected areas)
  • Jurisdiction and reporting on the maritime domain: to provide information on geographical data relating to administrative boundaries establishing jurisdiction (LES, LTM, LAM, lateral boundaries of prefects, etc.) or defined for reporting purposes (e.g. vocation zones of strategic façade documents).

The themes are structured in the same way with an interactive map based on a visualisation via This does not mean, however, that all the data on this portal are produced or disseminated by the Shom, nor that it is limited to the datashom layers: reference data produced by other organisations are also accessible (e.g. marine protected areas in the "environment" theme, which are produced by the Office Français de la Biodiversité and disseminated on the lizmap infrastructure).

Thus, for each data layer described in the "Data" section, the following are clearly specified: the referent of the regulatory limit, the producer of the digital geographic data (from the legal reference text) and the disseminator of the reference data (access point to the reference data, usually in the form of a stream).