In navigation, there are two primary types of course lines that
can be plotted, a great circle and a rhumb line. The great circle
provides the shortest distance between any two points on the globe,
but requires that the course (and headings) be continuously
adjusted. A rhumb line results in a longer distance to travel, but
allows for a constant course (or heading) to be maintained. By
definition, a rhumb line (also known as a loxodrome) crosses all
meridians at the same angle.