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