What s the name of this book from my childhood?

There s this book about a kid who rides a box down a river and ends up being swept into a cave. In the cave, he meets an old (?) man and his dog who have been trapped in the cave for a while. The man and the boy live off of crayfish (I m pretty sure) while trying to escape the cave. Please help, I ve literally lost... show more There s this book about a kid who rides a box down a river and ends up being swept into a cave. In the cave, he meets an old (?) man and his dog who have been trapped in the cave for a while. The man and the boy live off of crayfish (I m pretty sure) while trying to escape the cave. Please help, I ve literally lost sleep over this goddamn book. I just want to be at peace.
4 answers 4