A U. S. Army Corps of Engineers' barge, at Lake Washington Ship Canal and Hiram M. Chittenden Locks, Seattle, overflows with large woody debris, derelict objects, waterfront debris and other sources of drift, that may damage vessels or threaten public health, recreation or the environment at publicly maintained commercial boat harbors. Seattle District's MV Puget patrols the inland waters of Puget Sound and collects the debris and obstructions to navigation, cuts them down to more manageable pieces and places them on the barges for transport.