Abstract: An encapsulated underwater excavation assembly for removing solid materials (such as mud, soil, vegetation or debris) from a water bottom including, without limitation, during pile driving or installation operations. The excavation assembly can be contained within a housing that beneficially fits within an inner bore of a piling or other tubular member. A rotary motor having a cutting blade mechanically cuts solid materials while a centrifugal pump moves cuttings away from the lower portion of the excavation assembly for facilitate efficient installation of a piling.

Abstract: An encapsulated underwater dredge assembly is operable at depths up to 1,200 feet or more. The underwater dredge assembly has multiple cutting assemblies, beneficially disposed around a centrally positioned dredge pump; each of the cutting assemblies can rotate in clockwise or counterclockwise directions, as desired. All components of the dredge assembly are hydraulically powered and operated.