In the past two weeks Ghana, Pakistan, Norway, South Africa, Iceland, Denmark, France, Vietnam, Nigeria, Sri Lanka, Kenya and others have delivered boxes of documents to the commission’s premises in New York.
The hefty files of detailed paperwork – one Australian submission ran to 80 volumes – are the culmination of years of underwater exploration by each state, plotting submarine contours that mark the outer edges of the continental shelf.
The complex rules of the UN Convention on the Law of the Sea permit states to extend their control and exploitation of the seabed beyond the traditional 200 nautical mile limit and up to 350 nautical miles offshore.
The precise extent of each claim frequently involves establishing the foot of an underwater continental slope, thousands of feet down in the chilly, dark oceans – and then measuring 60 miles outward.
Some claims, usually the legacies of unresolved international conflicts, are mutually exclusive, generating fresh diplomatic unease along the fissure lines of ancient boundary disputes. Before Wednesday, the UK will present its claim for the seabed surrounding the Falklands, South Georgia and the South Sandwich Islands in the South Atlantic.
The submission is bound to overlap with the Argentinian claim sent in last month which insisted that the waters and extended continental shelf around all those islands belonged to the government in Buenos Aires. The French have raised hackles by claiming the seabed near their Pacific island territories.
The 13 May deadline applies only to those states that were signatories of the original treaty ten years ago. Other states, which signed at a later date, have more time left to submit their claims.
The United States has still not ratified the UN Convention of the Law of the Sea, but the prospect of neighbouring countries such as Canada and Russia carving up the seabed for exploration is rapidly shifting opinion in Washington.
Greenpeace and other marine environmental groups have derided the process as a series of colonial land grabs. Britain will have submitted several major claims, all in the Atlantic, by the end of this week: around Ascension Island, the Falkland Islands and in the Hatton-Rockall Basin to the west of Scotland.
The UK has signalled its interest in the continental shelf that slopes away from the British Antarctic Territory. All territorial claims at the South Pole are, however, formally frozen by the Antarctic Treaty to which the UK is a signatory.
Britain, France, Spain and Ireland have also lodged a shared submission for a 31,000 square mile tract of the ocean floor on the edge of the Bay of Biscay.