The door is locked and the cold water is still coming in. You could still break the door down, though, if you can endure the cold.

Endurance: Break down the door. [unknown]

Otherwise, you may examine the mural.

Or hope that the water is just an illusion.

Strict Mode (In Strict Mode, the game will not show you options that require a skill you do not have. In non-strict mode, these options will be greyed out but you can still cheat and access them. You can switch modes at any time.)