Canada’s Ocean Estate
A Description of Canada’s Maritime Zones

Canada’s ocean estate covers a surface area of approximately 7.1 million square kilometres. This represents an area equivalent to about 70 percent of Canada's land mass.

The 1982 United Nations Convention on the Law of the Sea (UNCLOS), which was approved by Canada in 2003, provides a description of maritime zones.

These maritime zones are required under international law to:

  • outline the range of sovereign rights that can be exercised by a coastal state in these areas of the sea (under the UNCLOS, the rights of a coastal state diminish with distance from its coast); and
  • outline the rights that can be exercised by other countries when they wish to undertake activities in these areas of the sea.

The six maritime zones, as outlined under the UNCLOS and stated in Canadian law in the Oceans Act, are:

Canada's Maritime Zones Internal Waters Territorial Sea Baseline Continental Shelf Continental Shelf Territorial Sea The High Seas Exclusive Economic Zones Contiguous Zone

This section of the site describes each of these maritime zones and Canada’s rights within these zones, as well as other elements of the UNCLOS framework (including the Baselines and the Area).


Measurements of areas of the sea are made from baselines. The normal baseline is the low-water line along the coast, islands, rocks and even low-tide elevations as marked on large-scale charts officially recognized by the coastal state. Where a coast, such as Canada’s, is very irregular, drawing straight baselines joining appropriate points on the coast is an accepted practice.

Basically, all marine areas seaward of the baseline are considered "offshore" and all marine areas landward of the baseline are considered "internal waters."

Canada’s straight baselines have been drawn using a list of reference points permitted under the UNCLOS. These are set out in regulations in the Oceans Act.

There are a few places along Canada’s coast where baselines have not been drawn due to international legal considerations. In these places, for example, the Bay of Fundy and the Gulf of St. Lawrence, Canada has drawn "fisheries closing lines." The United States and European Union dispute Canada’s straight baselines enclosing the Arctic Archipelago.

Internal Waters

Internal waters are generally treated the same way as land territory, that is, the coastal state has full sovereignty over them. There are a few minor exceptions described in the UNCLOS.

Canada’s internal waters consist of all waters on the landward side of the baselines established to determine Canada’s territorial sea, or those areas over which Canada has historic or other title of sovereignty. Generally, all lakes, rivers and harbours are internal waters, including some, but not all, bays.

Canada’s internal marine waters have a surface area of approximately 2.5 million square kilometres.

Territorial Sea

The territorial sea is an area of the sea that has an outer limit extending 12 nautical miles measured seaward from the baselines.

The coastal state has sovereign rights over the territorial sea. Its sovereignty extends to the airspace, seabed and subsoil. In this respect, the territorial sea is similar to a state’s land territory. Ships of all states enjoy the "right of innocent passage" through the territorial sea, but they must operate under certain conditions respecting international norms.

Canada has exercised jurisdiction over the territorial sea on its east and west coasts out to 12 nautical miles since 1970, first under the Territorial Sea and Fishing Zones Act and now under the Oceans Act. The baselines for measuring the territorial sea were originally set in 1967.

Canada’s territorial sea has a surface area of approximately 0.2 million square kilometres.

Contiguous Zone

The contiguous zone is an area of the sea adjacent to and beyond the territorial sea. Its outer limit measures 24 nautical miles from the normal baseline.

This band of sea is a buffer zone where the coastal state may exercise control to prevent infringement of its customs, fiscal, immigration or sanitary laws and regulations within its territory or territorial sea. The coastal state may also punish such infringements.

The contiguous zone is located within the first 12 nautical miles of the exclusive economic zone.

Exclusive Economic Zone

The exclusive economic zone (EEZ) is an area of the sea adjacent to and beyond the territorial sea, extending out to 200 nautical miles from the baselines.

Within the EEZ, a coastal state has sovereign and jurisdictional rights over exploration and management (e.g. scientific research and protection of the marine environment), and economic exploitation of living and non-living resources in the waters above the seabed, in the seabed and beneath the seabed.

Within the EEZ, states other than the coastal state enjoy certain freedoms, notably those related to navigation and flight.

Canada has exercised its 200-nautical mile fisheries jurisdiction since 1977. Canada’s EEZ was formally established in 1997 when the Oceans Act came into force.

Canada’s EEZ has a surface area of approximately 2.9 million square kilometres.

“Arctic Clause”

Of particular importance to Canada is Article 234 of the UNCLOS, which allows Canada to enforce a strict pollution-prevention regime in the Arctic EEZ. Negotiated into the UNCLOS by Canada as the “Arctic Clause,” Article 234 is a specific provision concerning the prevention, reduction and control of marine pollution from vessels in ice-covered areas within the EEZ.

Under the provisions of the Arctic Waters Pollution Prevention Act, Canada currently exercises pollution jurisdiction to 200 nautical miles.

Continental Shelf

The continental shelf of a coastal state comprises the seabed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural extension of its land territory to the outer edge of the continental margin, or to a distance of 200 nautical miles from the baselines, whichever distance is greater.

Article 76 of the UNCLOS provides a complex formula for determining the outer limit of a state's continental shelf beyond 200 nautical miles. Determination depends on the thickness of sedimentary rocks, which underlines the idea that the shelf is the natural extension of a state’s land territory. The maximum limit is 350 nautical miles from the baselines or 100 nautical miles from the 2500-metre isobath (lines indicating water depth), whichever is greater.

Exceptions of the continental shelf

If a coastal state’s continental shelf extends beyond 200 nautical miles from the baselines (as in Canada’s case), the coastal state must submit scientific, technical and legal details about the limits of its continental shelf to the Commission on the Limits of the Continental Shelf (the Commission). The Commission is a United Nations body established under the UNCLOS. The Commission makes recommendations to the coastal state regarding establishment of its outer limit.

Canada has until 2013 to present information

The coastal state has 10 years from the time that the UNCLOS came into force to present information pertaining to its continental shelf to the Commission. Canada is currently collecting and analyzing scientific, technical and legal information in preparation of making a submission to the Commission. It is estimated that Canada’s continental shelf beyond the EEZ represents an area of about 1.5 million square kilometres on the Atlantic and Arctic coasts. Canada has no extended continental shelf off the Pacific coast. Since Canada ratified the UNCLOS in 2003, it has until 2013 to present this information to the Commission.

High Seas

The high seas is the area beyond the EEZ. No state has sovereignty or jurisdiction over the high seas. The UNCLOS specifically provides that no state may claim sovereignty over any area of the high seas.


The area is the ocean floor beyond the continental shelf. The UNCLOS states that it is the common heritage of humankind. No "single" state has sovereign rights to, or jurisdiction over, the area. Rather, activities in the area are organized by all states through the International Seabed Authority (the Authority), an authority created pursuant to the UNCLOS.

International Seabed Authority

States that are parties to the UNCLOS manage the mineral resources of the area through the Authority. The prime objective of this agreement is sharing benefits derived from mining minerals from the area seabed. Royalties from mineral mining are paid to the Authority to distribute primarily to developing states. The Authority also distributes royalties paid for exploitation of non-living resources of the continental shelf beyond 200 nautical miles.