Chen Fangcai (Center), inheritor of watertight compartment craftsmanship of Fu ship manufacturing, makes a special trip to investigate the wrecked ship Nanhai One at a museum in Hailing, South China's Guangdong province, Jan 29, 2015. The 30-meter-long merchant vessel, built during the Song Dynasty (960-1279), sank off the coast of Guangdong province about 800 years ago. [Photo/Xinhua]