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