Abstract: An apparatus and method for dredging under water ground layers includes the steps of providing a dredging device composed of a mechanical dredging component having a part operative to contact the under water ground layers and exert a dredging action; and at least one water jet effective to inject water under pressure in an area where the mechanical dredging component is operative; mechanically impacting the underwater ground layers with the part to fracture the underwater ground layers and form fractured material; and injecting water under pressure from the at least one water jet simultaneously with the mechanical impacting to remove the fractured material so that an improved break-away pattern of material is obtained and reduced wearing of said part.