In the waters of Fontaine, in the Morte Region, there is a Precious Chest. To access it and claim valuable rewards such as Primogems and Hydro Sigils, you'll need to solve a puzzle using the Operable Mechanism: Regulating Valve. In our guide, we'll walk you through solving the puzzle, obtaining the Precious Chest, explain the purpose of crystals from the Pneumousia Storage Box, show how to control the valve directly, and adjust the water level in the room.

How to Find the Underwater Precious Chest in Morte

The ruins with the chest are near the Statue of The Seven, not too deep below the surface. You can find the exact location by looking at the map provided below:

Dive towards the structure on the right – this will take you to an air pocket with the puzzle inside.

Inside, you'll encounter the Bubbler Seahorse – eliminate it so it doesn't interfere later.
In one corner of the room, there will be a Pneuma cluster, and in the opposite, flooded corner, a structure with Usia. Grab a block (or use a character with the corresponding element) and hit the latter.

Two crystals will fall from the broken box – pick them up, swim to the Regulating Valve, and place them inside.

Use the Xenochromatic Ball Octopus skill and hold to use it on the mechanism until the room is completely filled with water, and the chest icon appears, indicating its unlock. There you have it – the Precious Chest is yours.

Good luck in obtaining it!