Abstract: A method and system for cleaning an underwater floor is disclosed. The method includes: submerging a self-propelled underwater vehicle into a body of water, such as a basin, for example; directing the vehicle to traverse the basin floor; suctioning sediment particles from the basin floor as the vehicle traverses the floor; and providing a suction force to the vehicle. In one embodiment, the act of suctioning includes removing substantial amounts of particles smaller than a predetermined size from the floor while not removing substantial amounts of particles larger than the predetermined size from the floor. The system includes: the submersible, self-propelled vehicle for traversing the underwater floor; a first vacuum hood, coupled to the vehicle, for suctioning sediment particles from the underwater floor; and a first pump, coupled to the hood, for providing a suction force to the hood.