The Bismarck Sea lies in the southwestern Pacific Ocean within the nation of Papua New Guinea. It is located northeast of the island of New Guinea and south of the Bismarck Archipelago and the Admiralty Islands. It has coastlines in districts of the Islands Region, Momase Region, and Papua Region.
Like the Bismarck Archipelago, it is named in honour of the first German Chancellor Otto von Bismarck. The Bismarck Archipelago extends round to the east and north of the sea, enclosing the Bismarck Sea and separating it from the Southern Pacific Ocean. To the south it is linked to the Solomon Sea by the Vitiaz Strait.
On the North and East. By the Northern and Northeastern coasts of the islands of New Ireland, New Hanover, the Admiralty Islands, Hermit Island, and the Ninigo Group, through Manu and Aua Islands to Wuvulu Island and thence a line to Baudissin Point in New Guinea (142°02'E).
On the Southeast. A line from the Southern point of New Ireland along the parallel of 4°50' South to the coast of New Britain, along its Northern coast and thence a line from its Western extreme through the Northern point of Umboi Island to Teliata Point, New Guinea ( )
On the Southwest. By the Northeast coast of New Guinea.
Recent explorations in the Bismarck Sea seabed have yielded discoveries of mineral-rich beds of sulfides, copper, zinc, silver and gold. These findings are especially important because they lie in shallow, calm waters. Papua New Guinea owns the mining rights to these minerals under international law.