I don't know why I didn't read this sooner. Adventure on the high seas! Street urchins make good! Having to hide one's gender even though you clearly can do the exact same work! I could have done without the romantic subplot, and I'm betting that most boys who read this could do without it, too, but it's exciting enough all the same that I think I could sell this to nearly any kid, particularly when the dreaded historical-fiction book report rolls around. 
 The narrator for the audio version was fantastic, so I'm sad that my library consortium doesn't have the rest of the series on audio, too.