Rhumb line
（重定向自Rhumb）
In navigation, a rhumb line, rhumb, or loxodrome is an arc crossing all meridians of longitude at the same angle, i.e. a path with constant bearing as measured relative to true or magnetic north.
A rhumb line is, together with the Great Circle Arc and an isoazimuthal, one of the three lines that can be drawn between any two points on the earth's surface.