- "This reef is an area of calm and gentle seas of warm water. On a clear day, one can see to the peaks of Tristis. Care must be taken, however, as swift riptides may carry swimmers to dangerous currents along the ocean floor."
- —In-game description.
Somnus Reef is (including Ecclesia) the eighth location in Castlevania: Order of Ecclesia. The area has many similarities to the Kalidus Channel, being mostly underwater and reusing most of the environments present in that stage.
The surface of the sea here is peaceful, and on a clear day one can admire the peaks of Tristis Pass, but swift riptides may carry swimmers to the dangerous currents of the ocean floor, and to the dangerous creatures that live there. Somewhere in this area you may be able to find and rescue the siblings Serge and Anna.
Somnus Reef's boss is Rusalka, the water demon. Her room is located midway through the level, in an expansive undersea cave. She rules over the waters here and is presumably the cause of Somnus' violent riptides.
- Anna and Tom can be found in this stage by breaking the upper leftmost wall of the big room that hosts three Decarabias (Tom will eventually escape from Wygol Village and have his own rescue quest later in the game).
- Serge can also be found in this stage, inside the upper leftmost room at surface level on the way out.
- Castlevania Realm - Source for the images.