The Gold Dredge is one of the most effective ways for prospectors and small mining operations to recover gold from rivers and streams. Suction Gold Dredges work much like a vacuum cleaner to suck sand and gravel (and hopefully gold) off of the bottom of rivers, streams, and other bodies of water. A gasoline (sometimes electric) motor runs a water pump which creates a venturi, which in turn creates powerful suction at the end of the dredge hose. Material moves up the hose and is discharged into a sluice, at which point gold and other heavies are trapped and concentrated. Some Gold Dredges are equipped with an air pump or Hookah system which allows the dredger to work underwater for extended periods of time.