§ 842. Harbor improvements in Suffolk county. The board of supervisors of Suffolk county may provide for widening, deepening or dredging any bay, harbor, inlet or channel or for the construction of bulkheads, groins, jetties, docks or other similar improvements to the water or waterways within its boundaries at the expense of the county and may appropriate moneys available for general town or county improvements in aid of federal or state projects for such purposes.