Compass

A compass is a primary marine navigation instrument that shows a vessel’s direction relative to magnetic north, or in some systems true north. On small craft it is usually a magnetic steering compass mounted at the helm; on larger vessels it may be gyro or electronic. It provides an independent directional reference when displays, power, or satellite position are unavailable.

For boaters, the compass is essential for steering a safe course, checking electronic navigation, and maintaining control in fog, darkness, or heavy rain. It is used to convert a desired Heading into a course to steer, support Dead Reckoning if position fixes are lost, and cross-check GPS information when instruments disagree.

PredictWind routes, forecasts, and GRIB displays use wind and course directions that must be understood against the compass on board, allowing for magnetic variation and any vessel deviation. When using Weather Routing, compare planned bearings with the ship’s compass so the route remains practical at the helm.