[misha1967]

Originally Posted by DelphiUniverse

If you don't have the sun and it is night time you can use the north star to find true north as it will not "rotate" along the earth rotation. You can find the north star by finding the big dipper of 7 stars, the bottom end of the dipper will point directly to the north star, it should point north as you can see on the heading I have, I rotated the view a little bit to the right, you can see that it is just about north.

That, by the way, was one of the things that blew my mind about the Silent Hunter series: When it started using accurate constellations. Now that is attention to detail!