The Irish territorial seas, as defined by the Maritime Jurisdiction (Amendment) Act, 1987, extend to a distance of 12 nautical miles from baselines. The Irish fishery zone is defined in the Maritime Jurisdiction (Exclusive Fishery Limits) Order, 1976, and extends to a distance of 200 nautical miles from baselines, or where appropriate, to the equitable equidistant line between the State and another state.
Under the provisions of the 1982 United Nations Convention on the Law of the Sea, an exclusive economic zone is defined as an area beyond and adjacent to the territorial sea in respect of which the rights of the coastal state and the rights and freedoms of other states are governed by the relevant provisions of the convention. The convention provides that an exclusive economic zone shall not extend beyond 200 nautical miles from baselines. The coastal state has, subject to the provisions of the convention, sovereign rights for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters superjacent to the sea bed and of the sea-bed and its subsoil.
A change to a limit of 350 nautical miles for fisheries or exclusive economic zone purposes would involve an amendment of the convention. This matter has not been discussed in the UN fora concerning the convention. The question of an extension of fishery limits has not arisen for discussion within the EU.
The convention provides separately for the continental shelf. The continental shelf of a coastal state comprises the sea-bed and subsoil of the submarine areas that extend beyond its territorial sea to the outer edge of the continental margin. The outer limits cannot exceed either 350 nautical miles from baselines, or 100 nautical miles from the 2,500 metre isobath. The coastal state exercises sovereign rights over the continental shelf for the purpose of exploring it and exploiting mineral and other non-living resources of the sea-bed and subsoil.
Where the outer limit of the continental shelf extends beyond 200 nautical miles from baselines, the coastal state must establish the limits based on geological and geomorphological criteria and details of the limits must, in accordance with the convention, be submitted to the Commission on the Limits of the Continental Shelf before mid-May 2009 for approval. Ireland has designated continental shelf parts of which extend up to 500 nautical miles from baselines and are the subject of competing claims by other coastal states. Ireland's detailed submission to the Commission on the Limits of the Continental Shelf is in the course of preparation at present.