Four clippers (commercial vessels) are making their way from Victoriatown through the fictitious archipelago to Port Henry, aiming to deliver all the valuable goods they pick up at various islands. They compete against each other and strive to win the White Ribbon Prize the fastest vessel is entitled to get. However, their progress is obstructed by reefs and pirates. Apart from clever maneuvering, the only protection against pirates is the war ship stationing in Port Henry.