Here is the full list of all 18 Choice of the Pirate achievements.
Defeat the ghost ship.
Fall under the curse of the ghost ship. Congratulations on your zombification!
Become a spy for the Crown.
Save Jim the Cabin Boy from an untimely death.
Acquire two ships to launch your fleet.
Convince Evan Lark to open up to you.
Acquire one ship to launch your fleet.
Remove the threat of Blackguard from your future.
Acquire three ships to launch your fleet.
Earn the notice of El Sabio.
Capture your first target without sinking it.
Turn over your first bounty to the Crown.
Steer the Crown in the wrong direction.
Steal from the Pirate King! You've got guts, Captain.
Rescue a mermaid.
Defeat the Lusca.
Will those mutineers get what's coming to them?
Become the Pirate King.