But this 1903 novel is a fascinating early example of the thriller genre, and all the foundation-stones are there: a secret politico-military plot with nefarious traitors at its root, some good guys out to foil it, a red herring or two, a pretty girl, &c.
With its minute descriptions of yachting and obscure German coastal geography (most of the story takes place in the small islands and sandbanks near Emden), this book may not be for everyone, but I think most readers will agree that its two main characters (the curious and idiosyncratic Davies and his companion Carruthers, the narrator) are well-drawn and charming. And I'm sure that while modern readers find the danger Childers warns of here (a German invasion of England) unlikely, the original audience for this book certainly wouldn't have dismissed it casually.
A throwback to a bygone age? Perhaps, but only in the best possible way.