The pirate clans of the Festever Archipelago have a unique method of catching ships. A purple bayou bush grows in the lagoons and swamps of the many islands in the archipelago, which is a shortcut for ships carrying valuable spices and cloth from distant lands, and the bark of this bush can be boiled down to a thick tar.

Although it doesn't smell very strongly, when smeared on a ship's hull or spread in front of a passing ship, it attracts shoals of fern-tailed suckerfish, very common in those passages, which latch onto the hull in such numbers that the drag will slow even a galleon under full sail to an almost complete stop. The more the ship strains against the hundreds of broad fins spread below it, the more firmly they attach themselves.

The only means by which the ferntails can be removed is by prodding them off with a sharp stick, one by one. Meanwhile the pirate clans have piled into the outrigger canoes and are rowing as fast and hard as they can to board the wallowing vessel, relying on sheer numbers and ferocity to outfight their victims.