Chinanews, Shantou, July 13 - The underwater archaeological exploration plan for the famous Nanhai-II has been completed and submitted to Guangdong provincial government and the State Administration of Cultural Heritage for examination and approval.Archaeologists are draining the sludge from the area around the shipwreck in anticipation of further exploration.At present, 138 chinas have been discovered in Nanhai-II, all made in the Song (960 - 1279), Yuan (1271 - 1368) and Ming (1368 - 1644) dynasties. 10 of them bid fair to be collected by museums. Most of the chinas are made by local kilns in Guangdong, the rest in Jingdezhen of Jiangxi Province, containing precious information for studying porcelain making in China.Nanhai-II is about 18 meters long, and lies about 25 m below the water. It took the strenuous effort of 12 archeologists to survey and map its position, collect relics scattered on the seabed around it, and take photos.It is estimated that Nanhai-II struck a rock and sank. It is an important evidence of testimony to the existence of the Maritime Silk Road.