You wonder if the dog was heading for England knowingly, and what means it used to keep a steady course, since its rumline extended over the horizon and he had no compass, sextant or GPS:-D Did he orient himself to the direction of the seas, check the sun's position, or merely rely on his sense of smell?
I'm e-mailing this article to my sister in law who loves dogs and has eight, two of which are labs.
This story reminds me of stories of pets who get lost or left behind when an owner moves, and then trek hundreds of miles to turn up months later on the owner's new doorstep. Almost enough to make one believe in animal ESP!