Drowned!

From Introduction:

This short adventure is bonus content for the Barbary adventure zone book. As such, it details and interesting feature of that region in the Untamed Empires world, together with a plot to encourage roleplay around it. The "Unwanted Passenger" section is suitable for a group of four 150K characters, but if you follow some of the later suggestions it's easy to scale up the difficulty to include a whole ship of enemies. What we're talking about here is nothing less than the dead walking the islands off the Barbary coast...