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