dredge

dredge (http://definr.com/dredge)

     n : a power shovel to remove material from a channel or riverbed
     v 1: cover before cooking; "dredge the chicken in flour before
          frying it"
     2: search (as the bottom of a body of water) for something
        valuable or lost [syn: drag]
     3: remove with a dredge, usually from a bottom of a body of
        water