NavList:

A good point: we have to remember that, as far as we know (an extent that is pretty sketchy, at best) they had no concept of north, let alone latitude (although this is not the same thing at all as being without a sense of orientation).

Did they realise the world was a globe?  Again; no way of knowing.  Maybe not.

So their whole foundation for nav was quite different from the somewhat mechanistic Western approach (mud-groping along the English Channel notwithstanding).

However, their navigation worked.

Hey; you sailors of cold northern waters: does the sea flash for you?  Is it common to see splashes of coloured light at night when, for example, you dip your oars?