A huge steel box being loaded on a towboat at the port of south China's Guangzhou city on May 5, 2007. The steel box will be transported to the archaological site of "Nanhai No.1" off the shores of Guangdong province around May 8th. The steel box, measuring 35.7 m in length, 14.4 m in width and 12 m in height, weighing 530 tons, will be used to salvage the 800-year-old ship found at the "Nanhai No.1" archaeological site. (Xinhua Photo)

A towboat carrying a huge "steel box" will leave the port of Guangzhou in south China on Sunday morning to begin salvage work on an 800-year-old ship, the most precious ancient ship found so far in the world.

The towboat with the "steel box" will sail for 2 days before reaching the working waters, some 20 nautical miles west of Hailing Island of Yangjiang City in south China's Guangdong Province, according to the Guangzhou Daily.

The sunken ship, which dates back to the early Southern Song Dynasty (1127-1279), was the first ancient vessel discovered on the "Marine Silk Road" of the South China Sea and was named "Nanhai No.1", meaning South China Sea No.1.

Nanhai No.1 was found accidentally in 1987. The ship, more than 25 meters long, is the largest cargo ship from the Song Dynasty so far discovered. The total value of the shipwreck may be over 100 billion U.S. Dollars.

Green glazed porcelain plates, tin pots, shadowy blue porcelains and other rare antiques have been found during the initial exploration of the ship. Archaeologists estimate that there are probably 50,000 to 70,000 relics on the ship, and that the archeological value of unveiling Nanhai No.1 is no worth less than discovering the terracotta warriors of the Emperor Qinshihuang.

The huge "steel box" will be used to salvage the ship with 2 meters of silt that covers it together to better protect the precious relics.

After salvage, the ancient ship, with its silt, will be put in a huge glass pool, in which water temperature, pressure and other environmental conditions will be the same as on the sea bed where the ship has slept for 800 years.

Archaeologists will then conduct thorough excavations of the ship in the pool.

It is estimated that the ship will surface in mid July, by which time questions, such as which port was the ancient ship's destination, and how did it sink, will be addressed by archaeologists.

Editor: Donald