Tristan Gooley is, according to his website, a “natural navigator”—by which he means that he navigates using nature, not that he’s just intrinsically good at navigating. He set out his stall with his first book, appropriately entitled The Natural Navigator, which is all about navigating using the sun and stars, the land and water, the plants and animals. And Gooley is an equal-opportunities naturalist—he’s quite prepared to navigate around town using the orientation of satellite TV dishes (they generally point southeast in the UK) and the route of helicopters (they’re legally required to avoid over-flying built-up areas as much as possible, so have a tendency to follow rivers through the city).
How To Read Water is his third book about natural navigation, a successor to the compendious The Walker’s Guide to Outdoor Clues and Signs. As the title suggests, this one zeroes in on water in the environment—and, in trademark style, Gooley is just as happy picking up directional clues from the behaviour of ships as he is from the distribution of puddles. He’s also refreshingly relaxed about what “natural navigation” actually means to the people who read his books—he knows that most of us are going to read this stuff out of curiosity about the outdoor environment, and few will actually throw away their GPS and compass. That’s fine with Gooley—although the book is loosely structure around the “natural navigation” concept, what shines through is a simple delight in just being out in the world, with a heightened awareness of the subtle cues that nature always provides.
The subtitle hints at the structure of the book—Clues, Signs and Patterns from Puddles to the Sea. Gooley starts small, with a glass of water in the kitchen, and expands the view steadily from puddles to rivers to lakes to ocean waves, currents and tides. Interspersed are digressions on the sound of water, the behaviour of fish, navigating at sea using the stars, the marking of ship navigation channels, and many other things.
Indeed, it begins to feel like a bit of a rag-bag. There has to be a diminishing return to this sort of book, and with this third volume I occasionally felt that Gooley was casting around for almost any unused material that he could roughly align with the concept of “water”. The chapter entitled “Rare and Extraordinary” is a case in point, containing a wild assortment of briefly noted phenomena that have something to do with water, but not much to do with navigation—for example, it includes short notes on flying fish, braided rivers, and amphidromes (points in the open ocean that experience a back-and-forth or round-and-round tidal flow, rather than a change in water level). He even mentions the green flash, an atmospheric optical phenomenon which has essentially nothing to do with water at all, and he addresses it so briefly that you can find out much more about it from my own humble offering on the topic. It’s not clear to me why this chapter is included at all.
But the book has taken on such a wide remit that I think there’s something here for everyone, although I also suspect that most readers will encounter a chapter or two that they find themselves skipping through in frustration. (For me, that was the chapter entitled “Shipwatching”.)
That aside, there are two undoubted delights to be had. One is finding out something entirely new, as I did when Gooley discussed the anatomy of a beach, and the origin of rips and undertows. The other (perhaps even more satisfying) is encountering something that you have been vaguely aware of for a long time, but which Gooley sets out in clear detail—a definite “Ah-ha!” moment. For me, that moment came during Gooley’s discussion of the anatomy of rivers. As a hillwalker, I’ve been crossing upland rivers for decades, and am often successful at finding a safe crossing-place over even initially unpromising-looking volumes of water. What I’m doing, it turns out, is exploiting a natural alternation in rivers between riffle and pool—I’m unconsciously seeking out the rapidly moving shallow sections (“riffles”) that are easier to cross than the deeper, slower pools. I’ve also long had an aversion to starting a river crossing on the inside of a meander loop, aware that I’m likely to find myself wading into deeper water as I progress. Gooley explains this phenomenon in terms of the thalweg, the line of maximum flow, which tends to stray towards the outer bank of a curving river.
And I learned some new words, which any reader of this blog will know is a Fine Thing. For instance, the tendency of some deciduous trees to retain their brown leaves throughout the winter (think of all those messy beech hedges, stuffed with dead leaves) is called marcescence. Which, I find after a bit of my own research, comes from the Latin marcere, “to be faint or languid”.
Occasionally things go wrong. If “a cube of water as tall and deep as the average person” weighs “almost three tonnes”, then an average person is about 1.4 metres tall (around 4 feet 7 inches). And I found the explanation of tides a little garbled, mixing gravity and centrifugal force in a way that wasn’t at all clear.
But over all, as with his previous books, there’s much to delight and enlighten. It’s an entertaining gallop through the complexities of hydrodynamics. On which topic, I’ll sign off with a statement attributed (perhaps apocryphally) to the physicist Horace Lamb, which Gooley quotes appreciatively:
I am an old man now, and when I die and go to Heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. About the former I am rather optimistic.
Horace Lamb, at a British Association meeting in 1932