The Water Tank is a room in the Cryosphere in Metroid: Other M. As the name implies, it is full of water, and by association, Skulteras. Samus must dive into the water to open a hatch. This will drain the water from the room (along with Samus) and flood the connecting room. When Samus returns, she is ambushed by two Kyratians. A pathway in here leads to a Missile Tank.