David Lewis also wrote (among about a dozen other books) 'We the Navigators - The Ancient Art of Landfinding in the Pacific', a fascinating and very readable book which explores how the Pacific islanders navigated. David Lewis tracked down the few surviving traditional navigators, and not just spoke to but went on voyages with them to understand their methods. They showed astonishing feats of navigation, amazing Lewis who was by that point a very experienced sailor.

Its a while since I read it (must do so again), but what sticks in my mind are methods including being able to sense the combinations of up to three or more different swells to judge direction, weather, wind shifts and the proximity of land. This was considered a strictly male skill, as they said they could feel these through their testicles (they knelt down when they really needed to concentrate on this). They also had detailed knowledge of distances and directions which were not written down, but passed orally through generations of navigator families.

Like many other cultures different to our own they had a completely different conception of geography and the disposition of places in relation to one another. Their 'mental map' of directions was related to where particular stars would rise from the horizon, but they could identify directions in cloudy weather, and knew about the positions of stars which were invisible from their location and apparently known only from voyages, undertaken several generations before, to distant other island groups.

However, if it's understated writing and endurance in icy climes you're after you are unlikely to do better than 'The Worst Journey in the World' by Cherry Apsley-Gerrard. Not a sailing book, but an absorbing, thrilling, thoughtful and deeply moving account of Antarctic exploration by someone who was in Antarctic with Scott (who's fatal attempt at the South Pole was but one part of a bigger 2 year expedition). The 'Worst Journey' of the title is not the pole expedition (though that features in the book), but an earlier, near fatal, three man trek (without Scott) in the Antarctic winter - permanent dark, unimaginable temperatures - across uncharted territory, purely for scientific curiosity! Typically, he loves Scott (though in a strictly manly, Edwardian sort of way, you understand!), and reckons him all the greater because he fights and (in Apsley-Gerrard's eyes) rises above his weaknesses (uncharismatic, not particularly strong, poor judge of men, prone to depression, etc.) to become a true leader. An amazing book, one of my favourites of all time.