The Fiendish Flagship

From the introduction: The Fiendish Flagship is intended for four characters with an average party level (APL) of 9. Characters who complete this adventure should earn enough experience to reach halfway to 10th-level. A crime lord's yacht is docked in the harbor leaving him open to attack. This campaign takes place in Arden, although it can be set in your own world. Any party composition should be able to finish the adventure with intelligent play.