Grandpa lent me his copy of this book when I was twelve. I loved it so much he told me I could keep it. I re-read this recently and it's as wonderful this time as it was the first time.
Learning about explorers and expeditions in school was a bit dry and dusty - this book really sparked my imagination.
The stories are vivid, wonderful and keep the interest level high. When I was younger I found the first couple of chapters a bit less engaging but once the raft hit the water I was hooked!