A vessel employed to remove sand, silt, or other depositions from the beds of rivers, harbours, docks, etc. which is effected as follows: The vessel, which is a species of open barge, being moored, a leather bag, the mouth of which is distended by an iron hoop, fastened to a pole of sufficient depth to reach the bottom, is put over the side, and descends to the bottom in an inclined position; two or three turns are taken with a rope round the pole, and a timber-head near the stern of the boat. A rope attached to the hoop of the bag, and passing over a small crow at the fore part of the vessel, is then brought to a winch, and the bag is gradually wound up by a man at the stern slowly slacking the rope which passes round the pole, thus allowing it to rise as it approaches the vertical position; at the same time causing such friction, that the edge of the hoop digs into the ground, and the leather bag receives whatever passes through the hoop. When the bag is raised above the side of the boat, it is swung into the boat by the crane, and its contents discharged into the bottom of the vessel.