What is the primary function of a compass in navigation?

The primary function of a compass in navigation is to provide direction by indicating magnetic north. This is crucial for navigators, as knowing the orientation relative to magnetic north allows them to determine their heading and navigate accurately. The compass works by aligning itself with the Earth's magnetic field, helping mariners to chart their course and make informed decisions while at sea.

While forecasting weather conditions, measuring speed, and displaying anchor depth are important aspects of navigation and seamanship, they are not the primary function of a compass. The compass itself does not provide information about weather or vessel performance; rather, it is strictly a tool for directional guidance, which is fundamental for safe and effective navigation.