, so here's how I do it without said Radar mod:
it couldn't be simpler. Just locate that tiny white white mark (Atka Island I think
), and click your ship to go to that spot. Once there, click your ship on the end of that staright line (international border), and Bob's your Uncle...
...and coming from north to south is exactly the same, but you click on the end of the ... oh feck it, just wasted 20 minutes of my life I will never get back
.
Ps. As you can see from the screenshots, I've actually got the Radar Mod installed, so then its just a case of clicking on that white line which cuts north to south through the map.
.