A friend recently observed how little he knew about the tides. Surprised, because he is an experienced sailor, I muttered something foolish about high and low, twice a day, moons, etc. Oh no, he said, there’s much more to it than that. After reading Jonathan White’s “Tides: The Science and Spirit of the Ocean,” I can only belatedly sigh, “And how!”

White has spent most of his life on the water, either sailing or surfing. For a while he conducted week-long seminars covering every imaginable topic aboard his 65-foot wooden schooner. His latest book finds the author on the exposed mudflats of the Bay of Fundy where millions of little shorebirds are fueling up on mud shrimp exposed by the Bay’s enormous tide. From here, he takes the reader on a tour of all the factors that make very different tides all over the world predictable. After that, he throws in a few surprises that can upset them all.

High-Low? Very little difference in Tahiti, and what “high” there is comes punctually at noon and midnight. Twice a day? Some ports in England have double high tides, others double low tides. The moon? The Pacific is more affected by the sun.

As he tries to make sense of all this, the author combines history, travel writing and science. From Sir Isaac Newton’s admirably straightforward theory (Newton ignored the effects of land forms, continental shelves, etc.) a model of astonishing complexity emerges, layer by layer.

At times it is tough going, particularly the science. I think that so-called “action at a distance” is the problem: a force you cannot see is hard to comprehend. So I cannot altogether hold it against White that some of his efforts at scientific explanation seem opaque. Attempts at metaphor are as likely to confuse as elucidate. Take the case of “resonance,” the key to the harmony of the universe, which we may experience as the point when one’s song in the shower makes the shower stall hum; thinking of the stall as the ocean and one’s voice the pull of the moon left me none the wiser.

However, other concepts are nicely handled by virtue of informative graphics. And his travel accounts – hallelujah! – are accompanied by excellent maps (a courtesy to the reader that is too often inexplicably missing). The author has picked out the sites of some of the world’s most extreme tides for personal inspection: besides the Bay of Fundy he visits Mont Saint-Michel, China’s Qiantang River for its tidal bore, and the San Blas islands off the coast of Panama, for example.

These forays into local culture give White scope for his considerable observational gifts and add another layer to the larger story. That the secrets of tidal motion are far from exhausted is obvious from the fact that, in the last 20 years, the Bay of Fundy’s record-breaking tides were challenged by those in Ungava Bay’s Leaf Basin in northern Quebec. It is currently considered a tie by no less an authority than the Guinness Book of Records.

It’s in Ungava Bay that White has one of his strangest experiences, collecting mussels under a canopy of ice in the precarious space temporarily left by an extreme low tide. Such an opportunity once represented a critical source of fresh winter protein for the Inuit, one of many traditional bonds with tide cycles the world over.

Equally strong is the very contemporary connection between a handful of extreme surfers and occasional monster waves at certain spots (new ones keep being discovered), such as the Mavericks off Half Moon Bay in California. They are the combination of far-away events and conditions that are anything but predictable. As one legendary surfer races down Highway One, he pulls out his laptop every 15 minutes to find where the “break” will be best, the latest off-shore buoy readings changing his ultimate destination all the way.

White’s research makes “Tides” a fascinating read. I wish he didn’t over-use the first person present tense in his writing, which makes his personal encounters seem breathless, self-conscious and far from spontaneous. There are also a couple of small but astonishing howlers, such as Edmond Halley (of comet fame) providing a precis of Newton’s work to “King Henry;” Charles II seems the more likely recipient. It’s a small point, but once spotted that kind of inaccuracy has a disproportionate impact on the reader’s confidence. Fortunately, it doesn’t change the fact that, thanks to White, I now know an awful lot more about tides.

Thomas Urquhart is a former director of Maine Audubon and the author of “For the Beauty of the Earth.”

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.