Some of this book is quite technical and was completely over my head, but a lot of it is fascinating to even the most unscientific of laymen. He charts the course of early explorers showing how the Polynesians, for example, were able to find their way across vast oceans. There are some stirring tales of exploration and endurance, and some wonderful "I didn't know that" type facts - did you know for example that virtually everyone veers to the left or the right when walking? And is the explanation for why on an unfamiliar route over a long distance people can, quite literally, end up walking in circles.
A wonderful stirring read, that just makes you want to go out and do something adventurous.