The boundary is, however, broken by the Timor Gap, where Australian and East Timorese territorial waters meet and where the two countries have overlapping claims to the seabed.

The 1997 treaty establishing this and the western parts of the border, as well as that between Christmas Island and Java, has however not been ratified and is not in force.

[citation needed] The basis for establishing the boundary in the 1971 and 1972 treaties was that of the "natural prolongation" of the physical continental shelf.

The 1997 treaty extended it further west, terminating at A82 in the Indian Ocean where Australia's and Indonesia's exclusive economic zone limits diverge.

Christmas Island is an external territory of Australia located in the Indian Ocean 186 nautical miles (344 km) south of the southern coast of Java.

It runs to the south of the Australia-Indonesia seabed boundary and terminates in the Indian Ocean where the Australian and Indonesia EEZ diverge.

The boundary essentially follows the Provisional Fisheries Surveillance and Enforcement Line (PFSEL), a non-treaty status agreement made in 1981 between the two countries, and is generally based on the median line principle measures from the Australian mainland and Indonesian archipelagic baseline.

The first two treaties to establish the seabed boundary between Australia and Indonesia utilised the "natural prolongation of the continental shelf" principle.

Especially for the second treaty, Australia argued that the deep Timor Trough was the natural edge of its continental shelf.

The resulting boundary was therefore located closer to Indonesia and had potentially denied considerable share of petroleum resources from the seabed.

Despite the principle being agreed to via negotiations, its use had been a constant point of discontent on the part of the Indonesians, with its former Foreign Minister Mochtar Kusumaatmadja saying that the country had been "taken to the cleaners" by Australia.

The 1997 treaty saw Australia's natural prolongation argument prevail as far as the seabed (essentially the continental shelf) claim is concerned.

However, Indonesia's median line argument was accepted for establishing its rights over the water column or exclusive economic zone, resulting in the separation of the two types of boundaries.