What is a Rhumb Line?

A Rhumb Line is defined as a line on the Earth's surface that intersects all meridians at the same angle. This characteristic means that a vessel following a Rhumb Line will maintain a constant compass bearing throughout its course. This is especially useful in navigation, as it simplifies the process of steering and ensures that a ship remains on a steady heading.

Unlike other types of navigation paths, such as the great circle route, which is the shortest distance between two points on a sphere but requires constant course adjustments, the Rhumb Line allows a navigator to plot a straight line on a Mercator projection chart. This straight-line course can be followed more easily in practical navigation, even though it is not the shortest distance.

The other options do not accurately describe the concept of a Rhumb Line. While it may be contrasted with curved paths determined by the Earth's shape or affected by currents, the defining feature is its consistent angle with all meridians, which captures the essence of what a Rhumb Line is in navigation.