I just finished reading this book with my 7 year old son, and am really impressed.
The story, set in the 18th century, is told by the diary entries of a boy on his first journey at sea.
The book is jam packed with information about the hard, and often gruesome life of a sailor on this merchant, soon to be pirate ship. If you ever need to know how to load a cannon, where to store your gunpowder or how to amputate a leg, then this is the book for you.
The fiction and the fact are combined in such a clever way that the your child will hardly notice (s)he's learning...it didn't do me any harm either!
I'm off to buy Castle Diary now...