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