37 Construction, installation, maintenance, repair, and servicing of desalination units, desalination plants and facilities, water treatment units, water treatment plants and facilities, water purification units, water purification plants and facilities, water storage units, pipelines, buoys, and docks; maintenance, repair, and servicing of ships, namely, maintenance, repair and servicing of ship operating equipment for power propulsion, navigation, steering, and crew habitation of a ship