Crack the code
A guide for the passwords on Byotr's Rock to help players get the achievement.

If you're looking up this guide, you're probably wondering what you missed in-game and why you can't find the clues for this password. You didn't miss anything in-game, because Byotr's Rock is a left-over bit of an ARG the devs put into the game. The solutions are not in the game, so using this guide will not result in any spoilers!

Byotr's Rock
In the Cult Islands territory, in the Breeding Isles region, there's an island called Byotr's Rock with an event exclamation point in front of it. Interacting with this will ask you for a password to bypass the "First Barrier".

First Barrier Password: GRABROCK
Second Barrier Password: CAPTAINSMITH

Entering both of these will give you a sequence in Morse Code and a clue about "looking outside yourself." This points you to solving the puzzle in real life for the ARG and has no further game-play effect. Congratulations, you just got the "Grr, Arg" achievement!

Original Post From: DarkE42

Win the Combat Campaign on the highest difficulty
Try to survive 4 rounds in a way that you board enemy ships and fight crew to crew (you get +145 gold instead of just +85 if u bombard the ship). Aim at the masts so you can get close.

After that upgrade your ship as much as you can with hull armor, weapon power, etc. Very RNG to get the right weapons but ur looking for weapons that do "massive hull damage". Video walkthrough of my own journey with that achievement takes approximately 30 min give or take depending on battle length.
https://www.youtube.com/watch?v=0x5uSp2uej0
Original Post From: Beckih404

Defeat a mutiny
A mutiny can happen when your moral is -100. It is quite easy to force this achievement and only takes a few minutes.
1. Start a new freeplay campaign
2. Do events until you can travel to a neighbouring map
3. Sell all your food at the starting harbour
4. Travel between maps, without food it will lower your morale every time you do that.
5. When you have -100 moral the next time you change maps the mutiny should happen.
6. Win the fight and this achievement is yours.

Original Post From: Jonaldinho10

Free a convict from a prison in port

Help the inhabitants of Crawford
When you reach Crawford Village (South-east of 2nd map to the south); Choose to help the people there. The achievement will unlock after successfully repelling the horror.

Discover the fate of your sister
To unlock the "Sister Act" achievement in Abandon Ship, you'll need to complete the following key quests:

1 - "The Redoubt": Discover what happened to the Redoubt.
2 - "A Wretched Hive": Interrogate the ex-Cultists at the Pit.
3 - "The Battle of Devilrock": Survive the Battle of Devilrock.
4 - "Mother's Grasp": Survive Mother's Grasp.
5 - "Reunited": Return Charles to Beatrice - alive.