Over the years I've developed criteria for judging new surveys of well-covered historical subjects. First, does it offer any new information? Second, does it offer a different perspective than other books on the same subject? Third, does it do a better job of covering its subject than its (sometimes innumerable) predecessors? In the case of a book like Sondhaus's history of the naval dimension of the First World War, it faces the added burden of being measured up against Paul Halpern's superb account of the subject, which was published not even two decades previously.
In terms of the first criteria, the answer is mixed. Sondhaus does take full advantage of the works published in the intervening period (such as Nicholas Black's book on the British naval staff during the war) to flesh out some new aspects to the story. None of it really revises our overall understanding to the conflict, but it does help him to offer a different perspective from Halpern. In this respect, Sondhaus does offer something different from Halpern's book, for while he covers many of the same battles and campaigns he spends his first chapters on the prewar naval arms race and focuses more on the broader political and strategic aspects of naval operations during the war itself. Because of this, Sondhaus's book is arguably a better overview of the subject than Halpern's book, especially for someone who wants to understand the impact of the naval war upon the overall conflict.
Does this mean that Sondhaus's book is better than Halpern's? The answer depends more upon what the reader is seeking than anything else. For a history of naval operations during the war Halpern's book remains unsurpassed for its coverage and thoroughness, as Sondhaus's own reliance upon it as a source can attest. Yet as an introduction for the uninitiated Sondhaus's book enjoys a slight edge. Fortunately we don't live in a world where we have to choose between the two books, and can benefit from reading both, yet Sondhaus's is definitely recommended first for a reader new to the subject before having them turn to Halpern's more richly detailed account.