Here is the full list of all 31 Windward achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Drop Grogolov on top of 3 or more enemies.
Opt out of a PvP match by using a White Flag.
Defeat a Pirate Captain.
Defeat 100 ships.
Complete 50 commissions.
Defeat an enemy by yourself without taking any damage.
Defeat two enemies back to back.
Successfully complete a commission to place a Guard Tower near a town.
Completely drive out pirates from a level 9+ region.
Establish a foothold in a region where your faction has no towns.
Open a Sealed Letter.
Make a town grow in size.
Upgrade your ship.
Achieve a skull kill rating.
Defeat 5 pirates.
Complete two consignments at the same time.
Do your first trade run.
Complete your first commission.
Find and equip your first epic item.
Unlock all ships.
Equip an item that will push any stat above 1000.
Become a true pirate. Arrr!
Hire a follower.
Capture a level 9 or higher region in a co-op match.
Sink a pirate captain in a level 39+ region.
Sink another player in PvP.
Drive out pirates from a level 39+ region.
Customize your ship's look.
Repair your ship while obscured by fog.
Achieve the Admiral reputation standing with any faction.
Complete the Strange Diagram quest.