The water level puzzle is the only one in chapter five of Call of the Sea, but it is a lengthy one. It begins after you traverse the first underwater section and emerge in a cavern with primitive huts surrounding another watery patch.
Look around and inside the huts. Each one has a different mark denoting it and a plinth with a button that you can push. The huts you can view have the following marks on them:
- Green human hand hut – To your left as you enter the cavern
- Green scratch mark hut – To your right as you enter
- Purple swirl hut – Across the way along a rocky path
- Red amphibian hand hut – Walk right past the scratch mark hut. There are two routes that branch off next to the defaced mural. Head up the left path to find it
- Yellow human hand hut – Continue up the path from the red amphibian hand hut to the huts at the very top
Retrace your steps and travel down the path that is right of the defaced mural. You will come across two columns with the five colored marks on them at specific heights. Look at the marks to draw them in your journal. You need to push the buttons on the plinths outside each hut in the order that they appear on the columns. The order that the buttons must be pushed in is as follows:
- Green human hand
- Yellow human hand
- Red amphibian hand
- Green scratch
- Purple swirl
The purple swirl button isn’t found on a plinth. It is the final button you must press on the stone head in the image above. Once that has been touched, the two columns will drop to the level of the water below. Each column has another button on its top that needs to be pressed. Head back down the path to the right of the defaced mural and push the first column’s button. Walk along the newly created path and interact with the portal to become a hybrid animal.
In the water section, you need to reverse the water flow on two of the columns. You will have tackled one of these at the beginning of the level. Swivel the mechanism 180 degrees and pump the black ooze through it to reverse the water flow on both columns. After the second is reversed, head back to the first. Push the button on a rectangular block to open a door down to the left. Swim quickly through the four columns, as the door is on a time limit.
Revert back to a human using the portal in the next area. Push the second lowered column’s button to reduce the water level further. Walk along the newly created path and touch the next portal to become a hybrid. Watch the resulting cutscene and you will unlock the Dark Water Ride achievement.