Compass use in navigation

Timeline

1. c. 1088–1120Kaifeng, Northern Song capital · Central PlainsNorthern Song texts such as Shen Kuo's Dream Pool Essays record magnetic needles pointing south; sailors and merchants began trial use of magnetic needles for direction on land and coastal voyages, laying the material foundation for sea-going application.
2. c. 1127–1260Lin'an (Southern Song capital) · JiangnanZhu Yu's Pingzhou Ke Tan of the Southern Song explicitly records sea ships using magnetic needles to point south; compass and needle-plate structures tended toward standardization, and merchant ships under the Maritime Trade Supervisorate were commonly equipped, supporting Southern Song–Nanyang trade routes.
3. c. 1261–1270Quanzhou port · FujianAfter the Yuan unification, maritime trade flourished unprecedentedly; merchant ships at ports such as Quanzhou and Guangzhou used magnetic-needle compasses to maintain Indian Ocean and Southeast Asian routes, corroborating the eastern navigation technology described in the Travels of Marco Polo.
4. c. 1405–1500Longjiang Treasure Ship Yard, Nanjing · JiangsuZheng He's fleet used precise compasses for navigation on seven voyages to the Western Seas, combined with star-altitude techniques and sea charts, bringing Chinese magnetic-needle navigation technology to the peak of large-scale application and promoting its westward spread via the Indian Ocean.