I liked the mystery part of the plot better than the way the relationships developed. I don't think I'll get this for my whole class, or even a small set for a literature group. It will make a great book-talk, though. In the official book leveling system I use, it is classified in the same category with Maniac Magee, Dicey's Song, and H.P and the Half Blood Prince. I think that once you get this far up into any leveling system, you have to be careful. Different books will challenge different students for different reasons. Sometimes it's the complexity of the plot and not just the challenging words or longer sentences that make a book hard. Sometimes it's the unfamiliarity of a particular setting, and sometimes what's hard is the language and tone of a strong "voice" telling a first-person narrative. The voice of this book would be highly accessible to my students but the setting has lots of things related to the ocean, to fishing boats, and to the Florida Keys--- a setting that will push many of my students to learn many new words.
Here's my plan for this book. I'll buy two paperback copies and then I'll book talk it. They can partner read it, if they choose. I have this vision next year for reading workshop of creating a culture of supportive partnering and teaming where we are all working hard to help each other grow stronger as readers.