Traditional colorful decorations are painted on the ship. [Photo provided to chinadaily.com.cn]

The "Watertight Capsule" was a significant invention of ship building in ancient times. Cabins were divided by partitions, and became watertight capsules, cutting off their connections with the cabins next to them. The principle was applied to Zheng He's fleet to strengthen the ships and allow them to slice safely through the sea. With the seven voyages of Zheng He's fleet, the watertight capsule technology spread all the way to Europe and was gradually adopted by shipbuilders around the world.

A worker saws the wood for rebuilding the ancient ship. [Photo provided to chinadaily.com.cn]

Ningde still functions as an important harbor on China's stretch of the Maritime Silk Road, and has also inherited the skills needed to build Chinese treasure ships. The original shipbuilders started their work from the late Yuan (1271-1368) and early Ming (1368-1644) dynasties and the work has continued for 23 generations up to today. Passed on in an orderly way for 650 years, "watertight capsule technology" was selected as a national grade intangible cultural heritage item in 2008, and was selected for UNESCO's "list of intangible cultural heritage urgently needed for protection" in 2010. Time will witness its further passing on from generation to generation, and exhibit China's efforts to protect its cultural heritage.