China's first manned deep-sea submersible completed a Pacific Ocean dive to 5,057 meters (16,591 feet), surpassing current U.S. capabilities and setting a milestone in a race to explore for potentially vast resources in the deepest parts of the world's oceans.

The Jiaolong set the Chinese record at 6:17 a.m. Beijing time Tuesday in the northeastern Pacific, between Hawaii and the North American mainland, according to a statement on the website of the State Oceanic Administration.

The three-person vessel carried out various tests, including landing on the seabed several times, and took photographs of sea creatures during the operation, which lasted almost six hours and was the second of four planned dives, according to the statement.

The dive means that the Jiaolong—named after a mythical Chinese sea dragon—is capable of reaching 70% of the ocean floor, the state-run Xinhua news agency said, adding that the vessel was expected to attempt a dive to 7,000 meters—the maximum it is designed to withstand—in 2012.

If that dive is successful, it would allow the Jiaolong to explore 99.8% of the seabed and put it at the top of a list of just five manned submersibles capable of diving below 3,500 meters, where many rich mineral deposits are thought to reside.

Japan's Shinkai can go down to 6,500 meters, Russia's Mir and France's Nautile to 6,000 meters, and the U.S.'s Alvin to 4,500 meters, although an upgraded version of the Alvin, designed to reach 6,500 meters, is scheduled to be ready by 2015.

The capability of such vessels is significant as rising commodity prices mean there is growing interest among state-run and private mining companies in exploiting mineral resources under the oceans, which cover about 70% of the Earth's surface.

The British journal Nature Geoscience published a paper this month in which Japanese researchers claimed to have discovered vast deposits of rare-earth minerals—used in a variety of high-tech products—on the ocean floor east and west of Hawaii at depths ranging from 3,500 meters to 6,000 meters.

Chinese officials have said the Jiaolong is designed to explore for valuable mineral resources on the ocean floor.

The Jiaolong is diving at the site in the Pacific because China was granted rights to explore for minerals there in 2001 by the International Seabed Authority, a U.N. body that oversees mining in international waters.

ISA, meeting at its headquarters in Jamaica, also approved last week applications from China and Russia—the first from any countries—to explore relatively newly discovered deposits called polymetallic sulphides that form around volcanic vents in ridges on the seabed.

China applied last year to explore the site in the Southwest Indian Ridge, which bisects the ocean between Africa and the Antarctic. Russia applied to explore a Mid-Atlantic Ridge site.

U.S. scientists in an Alvin discovered polymetallic sulphides, which contain base metals that include copper, lead and zinc, as well as gold and silver, in 1979, when they found vents spewing superheated fluids on the ocean floor off the west coast of Mexico.

But many experts say that U.S. investment in such research has declined over the past two decades, even as some resource-hungry emerging economies stepped up their efforts to develop deep sea exploration technology.

Another obstacle for the U.S. is that it is hasn't ratified the 1982 U.N. Convention on the Law of the Sea, and so is only an observer, rather than a full member of ISA.

China, which has ratified the convention and is an ISA member, has been active in deep-sea exploration since 2002, when it launched a program that included developing the Jiaolong.

Chinese scientists using an unmanned submersible discovered potential polymetallic sulphide deposits at two sites in the Atlantic Ocean, two in the Pacific, and one in the Indian Ocean during a 10-month research trip that ended last year, according to state media.

The Jiaolong also planted a Chinese flag on the floor of the South China Sea last year, fueling fears in the region that China could use its newfound technology for commercial or military purposes in disputed waters. Chinese officials say the Jiaolong is for civilian use only.