This is a genre mash of Napoleonic naval adventure and a mystery novel. Kind of a strange pair, but it works quite well.
The plot concerns a pair of brothers who operate a privateer. One is an ex-navy officer and the other an artist and gentleman about town. The story begins with a battle in which they end up on a British Navy vessel captained by the former brother's old adversary. A murder soon occurs and the other brother is top suspect. So the only thing to do is find out what really happened...
Various twists in the plot and secrets reveal as the story goes on, with some storms and sea battles to spice it up.
It's good stuff. The characters are interesting and fairly well-drawn, and the naval action is too. The mystery is not so compelling (although that might just be my lukewarm interest in that side of the story).