#dredger  a barge or barge-like vessel used for dredging
  supertype:  #barge__flatboat__hoy__lighter  a boat with a flat bottom for carrying heavy loads (especially on canals)
  part:  #dredge  a power shovel to remove material from a channel or riverbed
     part:  #dredging_bucket  a bucket for lifting material from a channel or riverbed
     part:  #scoop_shovel__scoopshovel__scoop  the shovel or bucket of dredge or backhoe

No statement uses or specializes #dredger; click here to add one.