Which of the following is NOT a feature of a rhumb line?

A rhumb line, also known as a loxodrome, is a path on the Earth's surface that crosses all meridians at the same angle. One key characteristic of a rhumb line is that it maintains a constant compass heading, making it straightforward to navigate without requiring constant course adjustments. This feature allows for easier navigation over long distances, as mariners can plot a consistent angle on their course without needing to realign frequently.

The notion that it is not the shortest distance relates to the more direct route, which is typically a great circle. However, a rhumb line provides advantages in ease of plotting and maintaining a steady course, which can be beneficial in certain navigational contexts.

When considering the curvature of rhumb lines, they do tend to curve toward the poles due to the spherical shape of the Earth. This characteristic can sometimes complicate navigation if marshalled over longer distances, underscoring the unique contour of rhumb lines compared to great circles.

In summary, maintaining a constant course without adjustments is a definitive feature of rhumb lines, corroborating why it stands apart from the other characteristics listed in the question.