What is the major advantage of a rhumb line track?

A rhumb line track's major advantage is that it allows a vessel to steam on a constant heading. This means that as the vessel follows this track, it can maintain an unchanging compass direction. For navigators, this simplifies the process of steering the vessel, as they do not have to continuously adjust their course due to changing angles of bearing, which would occur while following a great circle route. This can be particularly beneficial for vessels that are not equipped with advanced navigation systems or for those operating in areas where adjusting for a great circle route may be challenging due to environmental factors.

In contrast, the other options present alternative characteristics or benefits associated with maritime navigation. The shortest distance between two points is actually represented by a great circle route, not a rhumb line. Additionally, while rhumb lines can be plotted on gnomonic charts, the comparison is typically more relevant for great circles, which visually appear as straight lines on these charts. Lastly, while a rhumb line approximates the great circle path in specific scenarios, it does not provide the optimal route in most cases, especially in high latitudes. Thus, the key advantage of the rhumb line is its ability to facilitate navigation through maintaining a constant heading.