For most of Chinese history, the compass that remained in use was in the form of a magnetic needle floating in a bowl of water.
You will often leave the needle floating on the water.
"There were so many ships the sea looked like a pool with pine needles floating on it."
Each had wandered all the night, through footway and skyway, unconscious of his surroundings, yet both were drawn inevitably together like two magnetized needles floating on a weed choked pond.
The typical Chinese navigational compass was in the form of a magnetic needle floating in a bowl of water.
It was a silvery needle, floating unsupported in the air.
This is countered by evidence of the temporal proximity of the Chinese navigational compass (1117) to its first appearance in Europe (1190) and the common shape of the early compass as a magnetized needle floating in a bowl of water.
Either way, you will have a needle floating on water!
After describing the engraved glassware of the instruments which were notable for their needles "floating at depth" CAR concluded that "it felt expensive."