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