A buoy provided preferably for ascending in the water from an initial submerged position. The buoy comprises a buoyancy element positioned at an upper portion of the buoy in the ascending direction. Further the buoy comprises a storing structure for an elongated member positioned below the buoyancy element in the ascending direction, wherein one end of the elongated member is connected to the buoy and the other end of the elongated member is connected to an object submerged in the water. The buoyancy element is provided to obtain a rotation of the buoy around its central axis thereby paying out the elongated member while the buoy is ascending essentially vertically in the water.