Haunted Ship is a young adult adventure novel that follows a group of friends on a summer vacation in Maine. The friends are excited to spend their time swimming, sailing, and exploring the coast, but they soon discover that there is a dark secret lurking beneath the surface of the water. One night, the friends are sailing when they see a strange ship in the distance. The ship is old and dilapidated, and it seems to be deserted. The friends are curious about the ship, so they decide to investigate. When they board the ship, they find that it is haunted by the ghosts of the people who died when it sank many years ago. The friends are terrified, but they are also fascinated by the ghosts. They spend the rest of their vacation trying to learn more about the ship and the ghosts who haunt it.