Rhumb Line Meaning in Sailing

A rhumb line (or loxodrome) represents a path that crosses all meridians of longitude at the same constant angle. On a standard Mercator chart, this appears as a straight line, which allows a sailor to maintain a single compass heading for the entire leg of a journey. While it is the easiest path to steer, it is not the shortest distance over a sphere (that would be a ‘Great Circle’ route). One specific example involves a navigator drawing a straight line on a map between two islands and following a 270-degree heading to reach their destination. For coastal sailing and shorter distances, the difference in efficiency is negligible, making the rhumb line the standard for most recreational navigation.