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