Maritime Use of the Compass

Timeline

1. 1088Northern Song capital (Kaifeng) · Henan ProvinceShen Kuo's Dream Pool Essays details rubbing iron needles with lodestone to make them point north-south, and records magnetic declination; this is a systematic scientific account of magnetic needle technology, laying the theoretical foundation for the maritime compass, though it did not yet specifically discuss sea use.
2. 1111–1119Sea routes off Guangzhou · South China SeaZhu Yu's Pingzhou Kétan records: sea vessels 'at night observe the stars, at day observe the sun, in cloudy darkness observe the compass,' and also describes determining position by sounding depth and examining mud; this is the earliest clear record in world literature of magnetic needles used for maritime navigation.
3. 1124Mingzhou to Goryeo route · East China SeaXu Jing's Illustrated Account of an Embassy to Goryeo records: at night when clouds hide the stars, a 'direction-pointing floating needle' is used to determine north and south, showing that by the late Northern Song, sea vessels were equipped with floating-needle compasses, the technology having spread from South China to the Mingzhou-Goryeo route.
4. 1127–1150Quanzhou port · Fujian ProvinceAfter the Jingkang southward flight, the southeastern coast became the center of trade, with Quanzhou surpassing Guangzhou as the leading port; in the 1140s, merchant ships commonly used the compass together with star-height measurement and depth sounding, supporting long voyages to Southeast Asia and the Arab world.