The Pardon Pusher Quest

The Pardon Pusher Quest is not really a quest, but it describes how to find the materials needed to craft the Pardon Pusher.

Walkthrough
The first indication of this "under-the-radar" quest is when the player obtains the book called "Blueprints for Pardon Pusher". The book explains an order issued by Captain Buffbeard who is looking for the materials to build this ship. There would be 4 teams, each led by a captain who would gather the materials. Captain Buffbeard leads one of the teams.

The teams are led by the following captains: The materials they are looking for:
 * Captain Bobo
 * Captain Buffbeard
 * Captain Bulgeye
 * Captain Rosebernard
 * Pirate Ship Helm Materials
 * Pirate Ship Hull Materials
 * Pirate Ship Sail Materials
 * Pirate Ship Rudder Materials

Each captain will appear on Battlemaster Settlements, near pirate villages. There can be only one captain per island. These captains must be killed and looted in order for the player to obtain the materials. Once defeated, the captain will never respawn. Instead, if the player goes back to the island, a different captain may spawn or even a Pirate Commander.

When the player has all the materials, the boat may be crafted. Once crafted, the materials will permanently disappear and are not obtainable in that particular save anymore.

Trivia

 * Captain Buffbeard is the boss of all the captains, and commissioned the creation of the Pardon Pusher. When killed, the player will receive his armor.
 * Even if you kill a captain, as long as you don't take the materials on his body, this captain can respawn on another battlemaster settlement. You can acquire their unique items multiple time that way.