caption: The image shows a drawing of a boat on a white background with the words "Dredge Boat for Excavating Rivers" written on it. The boat appears to be a dredge boat, with a stern, two masts, and a large cabin. The hull is made of wood and the sails are billowing in the wind. The drawing is detailed, showing the various components of the boat, such as the engine, rigging, and other features.