Animal navigation is magic. Nobody really knows how they do it. We can only suggest the senses they must be using, but how their brains convert this information into action is a mystery. In their heads are computers infinitely smaller, lighter and more flexible than the fantastic silicon chips that clumsy humans employ. Let us first consider what animals have to measure and, to make sure we cover the whole field, we shall look first at what giant tankers, nuclear submarines, Concordes and Apollo space-craft require. [Wing Commander Anderson's article was presented at the Young Navigators’ Meeting in London on 18 December 1979.]