A suction dredge is a powerful underwater-type of vacuum cleaner. It sucks up streambed material (rocks, sand, gravel, silt, gold and other minerals), passes it up through a suction hose, and runs it across a recovery system floating at the surface. Hand Dredge GoldSucker Prospecting Gold Gemstone relics Miner 1-1/2X42. $45.99. $12.50 shipping. Benefits charity.