Wu says that Song and Yuan governments encouraged maritime trade. According to historical records, when cargo ships docked in Wenzhou, crew were welcomed by local officials responsible for maritime trade. The owners were required to give part of their cargo to the government in duties before they could sell their goods or buy other goods in the city.

"What they brought to sell in Wenzhou was usually luxuries like spices, medicines, pearls and jewels. Of course they never returned with an empty ship, and bought porcelain, silk and tea in Wenzhou to sell elsewhere," says Wu, adding that the ships usually remained in Wenzhou for weeks at a time in order to sell all their goods.

When foreign traders were ready to leave, a send-off ceremony was often held by the local government, which included rituals to the god of the sea to pray for the ship's safety.