Clearing Bearings and Danger Angles

A clearing bearing is a pre-plotted compass bearing of a charted object that defines a safe boundary. As long as your observed bearing of that object stays on the safe side of the clearing bearing, you know you are clear of a charted danger.

Clearing bearings should be drawn on the chart during passage planning and noted on the cockpit card. They are especially useful for coastal passages where you need to keep a safe distance offshore or avoid an isolated danger.

A horizontal danger angle is a related technique: by measuring the horizontal angle between two charted objects (using a sextant or compass bearings), you can determine whether you are inside or outside a danger circle. If the angle is greater than the pre-calculated danger angle, you are too close to the danger.