Magnetic Compass Navigation Technology

Timeline

1. 960–1087Kaifeng (Bianjing) · Kaifeng CityIn the early Song dynasty, traditions of the sinan and south-pointing fish dating from the Han continued, using natural lodestone or magnetized iron needles to indicate direction. At this stage needles were mostly used for fengshui geomancy and overland orientation; mature open-ocean navigation procedures had not yet formed, but devices and experience were accumulating for later maritime application.
2. 1088Runzhou (Zhenjiang) · Zhenjiang CityShen Kuo described in Dream Pool Essays methods of magnetizing steel needles by rubbing with a bian stone, suspending them with silk thread, or floating them in a bowl of water, and for the first time clearly recorded that the magnetic needle points slightly east of true north (magnetic declination). This scientific statement provided a theoretical basis for the maritime compass, though Shen Kuo did not specifically discuss its use at sea.
3. 1101–1110Port of Quanzhou · Quanzhou CityZhu Yu recorded in Pingzhou Table Talk: pilots know the geography, observing stars at night and the sun by day, and in overcast weather they observe the south-pointing needle. This is among the earliest surviving documentary records explicitly using the magnetic needle for maritime direction-finding. Fleets at ports such as Quanzhou already used the compass alongside star observation and depth sounding, forming a composite navigation system.