1. compass: the compass is a tool for feng shui detection, and it is also a common operating tool for management style. It is one of the three-piece navigation packages.
2. Nautical chart: Nautical chart is a special marine map used for navigation positioning and ensuring navigation safety, and it is one of the three sets of nautical charts.
3. Ballast stone: Ballast stone is a stone used to stabilize the center of gravity when the ship is empty, and it is one of the three sets of navigation.