I have other things to do, but if you look into it you'll find that the 'Viking wreck' surveyed in 2002 was actually not Viking at all, but a British warship.

I have other things to do, but if you look into it you'll find that the 'Viking wreck' surveyed in 2002 was actually not Viking at all, but a British warship. Also, the couple of mentions of a sunstone in the Sagas is when on land, and not for navigation.