While traveling with her family aboard the S.S. "Euphonia," eight-year-old Corby Flood accidentally attracts the murderous attentions of five men, clad in bowler hats, called the Brotherhood of the Clowns, as she investigates the mysterious singing coming from the ship's hold.
Nine-year-old Fergus Crane's life is filled with classes on the school ship Betty Jeanne, interesting neighbors, and helping with his mother's work until a mysterious box flies into his window and leads him toward adventure.
In the spring of 1920, teenaged siblings Rebecca and Doug MacKenzie continue their adventures on their uncle's ship, sailing through a typhoon into the Celebes Sea in pursuit of a missing "gyrolabe" which may be connected to the disappearance of their parents.
The posthumous papers of Rebecca MacKenzie document her adventures, along with her brother Doug, in 1920s China as the teenaged siblings are sent to live aboard their uncle's ship where they become involved in the dangerous activities of a mysterious secret society called the Honourable Guild of Specialists.
In the eighteenth century sixteen-year-old John Spencer sails from England in his schooner, the Dragon, to the Caribbean, where he and the crew encounter pirates, fierce storms, fever, and a strange man who some fear may be cursed.
In eighteenth-century England, after his father buys a schooner called the Dragon, sixteen-year-old John sets out to sail it from Kent to London and becomes involved in a dangerous smuggling scheme.