By Quentin Sommerville
BBC News, Yangjiang, Guangdong province
Chinese archaeologists have raised a merchant ship which sank in the South China Sea 800 years ago while transporting a cargo of precious porcelain.
The Nanhai 1 treasury ship, built during the Song dynasty which ruled China from 960-1279, is believed to contain one of the biggest discoveries of Chinese artefacts from that period.
"It's the biggest ship of its kind to be found," said professor Liu Wensuo, and archaeologist from Sun Yat-sen University.
"It lay in about 25m (82ft) of water and was covered in mud - perfect conditions for preservation. Both the ship and its contents are in exceptionally good condition."
The salvage team began building a massive steel cage around the 30m (98ft)-long vessel in May in order to raise it and the surrounding silt.
The cage was made up of 36 steel beams, each weighing around 5 tons. Together with its contents, the cage weighed more than 3,000 tons.
The heavy lifting began a day earlier than expected at 0900 on Friday due to favourable weather conditions. It was completed two hours later and placed on a waiting barge.
As many as 6,000 artefacts have already been retrieved from the 13th Century vessel, mostly bluish white porcelain, as well as personal items from crew members, including gold belt buckles and silver rings.
A further 70,000 artefacts are believed to be still on board, many still in their original packing cases.
Underwater archaeology is a new field in China.
In the mid-1980s a number of ships, containing enormous hoards of Chinese porcelain, gold and silver, were found by foreign treasure hunters.
Their valuable cargoes were sold at auction houses in the West. At the time, China was too poor to bid for the artefacts.
The loss of such an important part of its history spurred the government into action.
Nanhai 1 will be the first major project to be undertaken by Chinese underwater archaeologists.
Professor Liu is confident that the salvage will be a success.
"This really is only the beginning, there are so many shipwrecks in this area, fishermen often snag artefacts in their nets, sometimes they even wash ashore," he said.
It will also give historians much-needed information on a time when China was trading with the world.
During the Song dynasty, most of the country's trade was with India and the Middle East. Later that trade would shift westwards.
The ship will be stored underwater in a massive tank in a new museum
"People often think of ancient China as being a closed society, but in the Tang and Song dynasties, China traded with the world - much like today," Professor Liu added.
The Nanhai 1 will eventually be moved to a new purpose built museum near Yangjiang in Guangdong province.
The dramatic building - still far from completion - is being built on the beach.
The ship will be stored underwater in a massive tank, in which the water temperature, pressure and other conditions will be identical to where it lay on the seabed, allowing visitors to watch as archaeologists uncover its secrets.
China has invested about $40m in this project, in the hope of reclaiming a part of the country's history, and this time ensuring it stays in Chinese hands.