Here Lies Ole Jack Bones: A 9th Level Adventure for 5th Edition

The town of Blackwater has a colorful history. Originally a pirate haven, it has since been reformed into a respectable port city with a ruling council consisting of the town's richest merchants. These days, most of the seaborn traffic that makes its way down the eastern seaboard stops off at Blackwater for one reason or another. Recently, however, there have been tales of a ghost ship preying on the shipping lanes. They tell stories of a thick mist that sets in followed by the appearance of a ship as black as obsidian flying no colors and helmed by the devil himself. 

The truth is, the spirit of the dread pirate Jack Bones has risen up to seek vengeance on the merchant princes who hunted him down and trapped him in a seaside cave, dooming him to die of starvation. A dying Jack made a deal with Undarra, the goddess of hatred. In exchange for a second chance at revenge, he'd plunder the seas in her name, killing all those who crossed him. When the bargain was struck, Jack's head fell from his shoulders and was replaced with a horrifying visage, his skull serving as a repository for his soul on Arden while his body wreaked havoc upon the seas. 

Ever since, Jack has piloted his ghost ship, The Lady Hate (named after Undarra herself), out into the night to prey on passing merchant vessels. Each night he leaves from the cave where he was left to die and each morning he returns before daylight can catch him. The merchant princes, fearful of their dwindling profits and the stories that have reached their ears, have put out a call for adventurers to seek out this dark vessel and slay its captain once and for all.