Moscow's North Pole stunt, with explorers planting a flag with a mechanical arm from a submersible, was denounced by some other Arctic countries as a crude land grab.
Russia says a ridge under the Arctic Ocean makes the pole Russian, even though the coast of Siberia is 2,000 km (1,200 miles) away. Greenland, administered by Denmark which also says the pole is Danish, and Canada are at the other end of the same ridge.
"Other coastal states have as good a case as the Russians," said Lindsay Parson, an expert on continental shelf law at the University of Southampton in England.
OPEN QUESTION
Croker said it was an "open question" whether any state could could back up a case for claiming the North Pole.
The polar dispute is about more than bragging rights to ownership of what many reckon is Santa Claus's home -- by some official U.S. estimates, the Arctic may hold a quarter of the world's undiscovered oil and gas.
"Companies can now exploit oil and gas in deeper and deeper waters," Parson said. "The more you know about resources the harder it is to be friendly in sharing the seabed."
No firm is able to drill anywhere near the North Pole, but global warming may make the region more accessible.
Drilling group Transocean says its Discoverer Deep Seas holds the world depth record for oil and gas drilling, set in 2003 at 10,011 feet of water in the Gulf of Mexico.
"We are building four new enhanced Enterprise-class drill ships (in South Korea) that will be able to work in water depths of 12,000 feet and drill wells 40,000 feet deep," said Guy Cantwell, spokesman for Transocean.
Any state missing the 2009 deadline risks losing U.N. recognition of the claim. Countries that have not yet ratifed the Law of the Sea Convention, including the United States, are not bound by the 2009 deadline.
The U.N. Commission cannot decide on overlapping claims, merely refer them back to governments to sort out -- a process likely to take years, or decades. Any extended rights will apply only to the seabed, not to fish stocks.
Experts say an extension of fishing limits to 200 nautical miles in the 1970s, the last big change of the ocean map, caused barely any conflicts. Britain and Iceland fought "cod wars", but with few casualties in clashes between frigates and trawlers.
Offshore disputes between neighbours such as Iran and Iraq are generally about resources closer to land.
Croker said the deadline migh even promote cooperation.
"It could be a trigger for states to sit down and try to sort out these issues," he said, noting that Spain, France, Ireland and Britain had made a joint submission covering the Bay of Biscay. "It can work in a positive way."
Norway, one of the few countries to have made a submission, said it cooperated closely with neighbours such as Russia and Iceland. "We have shared our data at expert levels," said Rolf Einar Fife of the Norwegian Foreign Ministry.
