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