Device for removing the growth on a ship's hull

Device for removing the growth on the steel hull (2) of a ship, which device comprises a cleaning element (3) and means for displacing this cleaning element over the hull (2), which means comprise at least one cable (4) which is arranged such that it passes underneath the keel of the hull (2) and to which the cleaning element (3) and means (5) for moving the cable (4) are connected, characterized in that the cleaning element comprises at least one mat (3) comprising a flat base (13) consisting of an elastically deformable material, which, at least at one side, is provided with a relief (14) of wear-and-tear-resistant, elastically deformable material, in or on which mat (3) at least one magnet (17) is provided for pushing this mat (3) against the ship's hull (2).