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