The black ooze frequency test is one of several puzzles to solve in Call of the Sea. It’s found in chapter three onboard the Lady Shannon shipwreck, but there are plenty of steps to complete it. If you’re struggling with any element of it, we’re here to help.
First, you need to turn the power back on. There is a campsite on the beach next to the shipwreck, but all of the lights are off due to a power supply issue. Follow the power cables from any lamp and they will all lead into the shipwreck. Head inside the hole in the hull and climb the ladder on the back wall. Take two lefts along the walkway and you will find the ship’s power generator.
There are four levers to pull. Flip the third, fourth, second, and first switches in that order to bring the generator online. To illuminate the ship and the camp lamps, you need to pull levers on additional power sub-generators. The first is next to the generator, the second is on the wall behind you where the walkway branches off in three directions, the third is outside next to the hole in the hull, and the fourth is in the campsite. For now, concentrate on flipping the switches for the sub-systems inside the ship.
Facing the sub-system on the wall at the walkway crossroads, head left. You will reach a dead end with a room to your left. Go inside to find the ship’s main office where a radio distress signal is playing. The black ooze frequency test is on a table on the right. Look for a note to the right of the machine, which will give you tips on how the machine works. Turn the machine on and the stones will start to levitate.
To solve this puzzle, you need to align the black ooze stones so that they are level with one another while they are levitating. When a stone is in its correct position, the green LED light underneath will light up. However, each stone rises and falls at different frequencies. These are dictated by the three dials that you can turn. The left dial causes the first and second stones to rise at different rates, the middle dial controls the second and third, and the right dial causes the first and third stones to rise and fall.
There are too many dial turns to write out an exact walkthrough to align the stones. The best way to line them up is to turn the dials up to their maxium frequencies so that all three stones are levitating at their highest point. You can turn each dial one or two places to the left, or right if you need to raise them, to intricately align them.
Once all three LEDs are lit up, the machine will give you three seemingly random coordinates. Nora will jot them down in her journal. Bear them in mind, though, as you will need them to complete the tidal organ puzzle later in chapter three.