A hydraulic dredge in which the suction action is augmented by a rotating propeller that operates at the point of suction. The cutterhead performs two functions: it cuts into and loosens compacted soils and soft rock such as coral, and it increases dredge capacity by channeling the soils into the end of the suction pipe. The efficiency of a dredge is based on its capacity to handle soils rather than water, and the cutterhead serves to maintain an optimum ratio of about 1 ft₃(0.028 m₃) of soil handled per 5 ft₃(0.14 m₃) of water.