What is a key advantage of the Gnomonic projection?

The Gnomonic projection is particularly useful in navigation because it represents great circles as straight lines on the map. This feature is essential for mariners and aviators who need to plot the shortest possible course between two points over the Earth's curved surface. By utilizing straight lines to depict great circles, navigators can easily visualize the most efficient routes for travel, which is crucial for planning voyages or flights.

In contrast to this, the other characteristics of the Gnomonic projection are not as beneficial for navigation. For instance, while distances may be more challenging to measure accurately, true shapes of landmasses are significantly distorted when using this projection. Additionally, rhumb lines, which represent constant compass directions, are not shown as straight lines on this type of projection. Thus, the unique advantage provided by the Gnomonic projection is its ability to clearly illustrate great circles, facilitating more effective navigation over long distances.