Question: When were the first magnetic compasses used by chinese ships?

context: No context provided
question: When were the first magnetic compasses used by Chinese ships for maritime navigation?
short_answers: 1111-1117
context: No context provided
question: When were the first magnetic compasses used by Chinese ships for navigational orienteering?
short_answers: 1040-1044
1040 -- 44

Answer: The magnetic compass is the most familiar compass type. It functions as a pointer to "magnetic north", the local magnetic meridian, because the magnetized needle at its heart aligns itself with the horizontal component of the Earth's magnetic field. The compass was used in Song Dynasty China by the military for navigational orienteering by 1040-1044, and was used for maritime navigation by 1111-1117.