It's a slim volume for those who love both water and words.

John R. Stilgoe's Shallow Water Dictionary is only a dictionary in the loosest sense of the word. Words are defined, yes, but not in any kind of easily searchable format. Rather, Stilgoe crafts a long-running essay -- perhaps better described as a free-style poem -- that expresses his love for coastal New England waters through an exploration of the words that describe them.

Too, it's a lament for words that have been lost, either dropped entirely from the English language or muddled through unclear connotations that confuse, for instance, a brook with a creek, or a rill with a river.

"In the speech of the marshes, definitions are sea-marks, and a wrong one here and there can turn a pleasant cruise into a very real crisis, say on a late autumn afternoon with a rising wind and skift of snow in the air."

The book is set within the context of Stilgoe's silent cruise through his beloved shallows and marshes, in an aptly named Essay, a "bilge-bottom boat" powered by oars or, when needed, "an elderly two-horsepower Evinrude outboard engine, about as tiny and unreliable as engines come, but a perfect compromise for the long passages along the deep channels."

Shallow Water Dictionary is a scholarly gem, perfect for quiet contemplation on a sunny day. It's brief -- just 59 pages, not counting the index -- and sparsely illustrated.