Here is the full list of all 25 Privateers achievements.
Defeat 1000 enemies across all plays
Slay a Kraken
Complete the tutorial
Get -100 reputation
Get 100 reputation
Get -50 reputation
Get 50 reputation
Win a game in treasure mode
Have 6 different classes in your crew
Have 6 non-humans in your crew
Survive 10 weeks in endless mode
Survive 20 weeks in endless mode
Survive 30 weeks in endless mode
Take the risk 10 times
Complete the Kondanese Monarchy quest line
Complete the Kondanese Republic quest line
Complete the Robot Artificers quest line
Your whole crew has died
Complete the Kraken quest line
Gamble and win
Equip a crew member with 3 heroic items
Purchase a Man-O-War
Purchase a Brigantine
Purchase a new ship
Complete a quest with only one crew member