Call of Cthulhu

Regarding skill checks. The percentages I list worked for me. Higher percentages will give you a greater chance of passing skill checks the first time. A quiet two-note tone will play every time you pass a check. IMPORTANT If you fail a skill check immediately dashboard then quit the game. Reload the game and you’ll be restarted from the last checkpoint. If you’re not fast enough then the option will be gone forever and you’ll be locked out. Since inventory and items do not carry over you'll have to restart the game If you do have to reload be sure to pick up all collectibles that did not save.


Chapter 2

After talking to Fitzroy the harbormaster the alleyway past the Stranded Whale bar will open up. Walk to the end and find a large open door on the left. Inside find three hidden items

LEVER - As soon as you walk in on the left-hand side on the floor behind the movable board.
RATCHET DEVICE - On the left-hand wall in a broken crate to the left of the roof support beam.
COGWHEEL - Turn 180% and look to the left of the beam on the other side of the room. Partially hidden between metal plates

From the cogwheel turn right and go up the ladder. Interact with the winch, then mount the ratchet device > cogwheel > lever, then turn the handle SKILL CHECK HERE [STRENGTH SKILL 50%]

Drop down through the grate and turn right at the bottom to wade through the water. A cutscene plays and after you'll get the achievement.

When you first start the game put all your points into strength. Then later after talking to the shipmaster put the extra points into strength that you get (should be two) go over to the allyway with the cop car go into the warehouse and pick up the 3 hidden items. They are pretty easy to find and go up the ladder and open the gate. After that just go through the water passage and it should pop!

This occurs on chapter 2 and just like "The Prohibition of Darkwater".. This requires another skill check, this time.. Strength.

As you see in my 100% Video guides, i put all CP points into Spot hidden and investigation skills and managed to unlock this on my first attempt on my first 2 playthroughs.
So after you deal with the guards with the drunk sailors, head towards the bar again but turn left down the street.
On the left hand side you can enter a warehouse.. You need to find 3 hidden items (Which aren't hidden that much).. On the left behind some pallets as you enter.. staying on the left in a trolley and on the right side behind a metal thing is the other.

Go up the ladder to the turning mechanism, put all 3 items on and then press and hold to work the grate.

If you go to 15:00 in my first playthrough video, you will see what you need to do and more importantly what a failed strength test looks like.
Theres a small subtle difference between a failure and a success, so watch it, and if yours does the same as a failed attempt.. BEFORE you finish it, IMMEDIATELY quit out, and start again, if you finish the test, the game saves and have to restart!

Hope this helps!

Playthrough 1

Playthrough 2