I have mentioned before (in glowing terms) David Gerr's Nature of Boats book. I had it in a stack of books on my desk that I had been referring to off and own. Dane ran across it and it struck his interest.

How many 7 year olds pick up Nature of Boats and proceed to start reading it? The first little bit he did out loud (some of the pronounciations are interesting :-)):

Then he decided to get more comfortable and keep going... it's well past his bed time, but I really don't want to discourage it :-)

David Gerr books available from Amazon.