Abstract: A bottom well of a vessel having at least one of a bottom and a broad side has a wall and cover-plate structure attached to the bottom or broad side for, together, defining the bottom wall. An inner space within the bottom well of the vessel has inside surfaces. A water inlet is in one of the bottom or broad side for communication of the inner space with outside water. A water outlet is in one of the wall and cover-plate structure for communication of the inner space with systems of the vessel. At least one resilient body is in the inner space for compensating for volume changes of water in the bottom well caused by the water freezing in the bottom well.