Missee Lee, Paperback/Arthur Ransome

The Swallows, Amazons and Captain Flint don't pay much heed to the harbourmaster's friendly warning as they set off for China. They are on a round-the-world voyage aboard the Wild Cat and it's been plain sailing for a hundred ports. But when Gibber, the ship's monkey, accidentally sinks their faithful boat things take a serious turn for the worse.