Abstract: A floating dock is provided for efficiently cleaning ship hulls and for reducing pollution problems associated with the cleaning of ship hulls. A method for cleaning ship hulls with a floating dock also is provided. The floating dock is ballasted and independently manoeuvrable. The floating dock has a ship hull receiving section which can be submerged at least partly so that a base part of the ship hull receiving section may be positioned beneath a ship hull. Cleaners are provided on at least one inner side of the ship hull receiving section to contact a side of the ship hull, and a debris collector may be provided to collect debris removed from the cleaning operation for later processing or dumping at a remote site. The floating dock can be self propelled forward and backward to reach the ship and can be self propelled laterally to clean the ship.