This dataset provides the boundary of New Zealand’s continental shelf, which is the area of seabed around a large land mass where the sea is relatively shallow compared with the open ocean.

The continental shelf is the seabed and subsoil of the submarine areas that extend beyond the territorial sea of a coastal state throughout the natural prolongation of its land territory to the outer edge of the continental margin.

In New Zealand’s case, the continental margin extends beyond the Exclusive Economic Zone in many places and the outer limits have been established on the basis of the recommendations of the United Nations Commission on the Limits of the Continental Shelf. Under UNCLOS, New Zealand exercises sovereign rights over the continental shelf for the purpose of exploring it and exploiting its natural resources.

Note: The boundary includes, where applicable, the delimitation of the boundaries of the continental shelf with Australia under the treaty of 25 July 2004. The delimitation of the maritime boundaries in the north with Fiji, Tonga and possibly France in respect of New Caledonia, have yet to be settled by treaty.

Maritime Boundary Definitions:

http://www.linz.govt.nz/hydro/nautical-info/maritime-boundaries/definitions#zones

Further References:

http://www.linz.govt.nz/hydro/nautical-info/maritime-boundaries