Here is the full list of all 52 Vendetta - there are Curse of Raven's Cry achievements.
Hire a full officer set
Sink 40 small galeons
Successfully board 50 ships
Sink 50 schooners
Get reward from Spanish Ally
Collect 1.000.000 reales
Find Unicorn Horn (Narwhals Horn)
Finish the game
Acquire a ship of the line
Save Marcus
Kill Marcus
Advance to level 25
Solve more than 100 quests
Sink 30 frigates
Sink 20 galeons
Earn 100.000 reales from trading
Sink 10 warships
Release 10 ships after boarding
Destroy a ship during boarding
Get reward from French Ally
Get reward from English Ally
Eliminate 100 beasts
Prepare any tincture
Burn 10 ships after boarding
Purchase a frigate
Get Max reputation as a Pirate
Purchase a small galeon
Purchase a warship
Purchase a galeon
Kill 50 human enemies using Fear skill
Collect 100 herbs
Use your Raven to steal something 100 times
Finish third chapter
Shoot 50 human enemies
Kill 25 human enemies using a knife
Eliminate 50 human enemies silently
Finish second chapter
Advance to level 10
Kill 100 human enemies on land
Have more than 100 items in your inventory
Finish first chapter
Fully upgrade the Serpent
Blow yourself up.
Advance to level 5
Kill 10 human enemies with explosions
Purchase a schooner
Win 10 games of dice
Naughty, naughty.
Finish Tutorial
Sink 500 ships
Waste 50.000 cannon loads
Use 100.000 reales on ship repairs