China's decision to send the Jiaolong manned submarine to explore a basin close to the Philippines may signal a new step in its approach to bolstering regional territorial claims, experts say.
But the survey mission risks stoking tensions with neighbours that hold competing sovereignty claims, they argue.
Jiaolong team leaders told state media they were preparing for the submarine's dive of more than four kilometres to the bottom of a South China Sea basin some time next year.
The exact location of the surveying mission has not been disclosed, but they are due to travel to the basin, which lies 200 kilometres west of Manila and north of the Spratly Islands.
Professor Zhang Mingliang, a specialist on South China Sea affairs at Guangzhou's Jinan University, said the deployment of the Jiaolong, China's most sophisticated submarine, might be part of Beijing's strategy to strengthen its territorial claims in the region.
But its presence so close to a nation already expressing concern over Chinese vessels violating its waters would almost certainly trigger a reaction from neighbours and other countries.
'If the Philippines believe that the surveyed area belongs to them, they will at least try to monitor, follow or even disturb the work,' Zhang said. 'The United States will definitely intervene, using various methods such as providing surveillance technology and equipment to the Philippines.'
Beijing told the Jiaolong team they would be joining The South China Sea Deep (SCSD), a civilian research project funded by the National Natural Science Foundation, an organisation directly affiliated to the State Council.
The SCSD, due to end near 2020, uses research vessels equipped with ocean bed surveying capabilities. The Jiaolong will make its first dive between April and May, according to the China Daily. But SCSD scientists are still trying to figure out how to accommodate the inclusion of the submarine, which reached depths of more than seven kilometres in the Atlantic Ocean last month.
They have held at least three brainstorming meetings since June last year, but are still working out how the Jiaolong's capabilities would be best employed.
'We don't have a clear idea yet. We don't even know whether we truly need a dive next year,' said Zhou Huaiyang , a professor with the State Key Laboratory of Marine Geology at Tongji University in Shanghai. Zhou has been a liaison between the civilian group and the Jiaolong management in the last few months.
He said researchers felt the only role Jiaolong could play was to obtain rock and liquid samples, which could shed light on the geophysical and chemical nature of the basin surface.
But even that information was far removed from the civilian project's primary objective, which was to understand how the basin was formed.
Solving the mystery could help geologists pinpoint mineral belts as well as oil or natural gas reserves.
'To understand the formation of the South China Sea basin requires us to map the geophysical structure up to 1,000 metres below the ocean floor,' said Fan Dejiang , a deep-sea geologist. 'Scientists mostly rely on ocean bottom seismic surveys to obtain the data. How deep can the Jiaolong drill?'