Tue, May 3, 2005, 4:57am (gregg) advises:
At sea? During the Day? snip They had no magnetic compass. They didn't
know there was True vs Magnetic North. snip

Yeah, at sea, during the day. You wait until the sun is at it's
highest, you look at a shadow, the shadow points north. Then you point,
and say, "Hey, that way's north". Simple. However, not exactly
precise. The Vikings didn't need to know about "True North", what they
needed was a consistent reference point, this allow them to have just
that.

Toward the end of the Viking age, they did have access to magnetic
compasses.

Check this.
http://members.aol.com/jvlambert/Norman/SunCompass.htm



JOAT
A highbrow is a person educated beyond his intelligence.
- Brander Matthews