Diagonal lines (Rhumb/Nav Lines)

[arakish]

Sorry for the necromancy on this topic, but I found it interesting to read what others wrote about something I already knew.

On the wikipedia link above, they have a diagram that show what I made in images some time ago (perhaps years) when a friend asked me why put them on a map I made for him. As mentioned in a previous post, rhumb lines cross latitudes and longitudes at a constant angle. But when you look at it on a globe, the line spirals to the pole. Attached are some images I made showing this.

rmfr

[Hai-Etlik]

Sorry for the necromancy on this topic, but I found it interesting to read what others wrote about something I already knew.

On the wikipedia link above, they have a diagram that show what I made in images some time ago (perhaps years) when a friend asked me why put them on a map I made for him. As mentioned in a previous post, rhumb lines cross latitudes and longitudes at a constant angle. But when you look at it on a globe, the line spirals to the pole. Attached are some images I made showing this.

rmfr

That's not actually a true loxodrome. Your map is in Equirectangular projection and a diagonal in it is not a line of constant bearing. A true loxodrome in this projection has decreasing slope as it gets closer to the poles. You need a Normal Mercator projection to get all loxodromes shown as straight lines.