Other times, it is pumped into barges (also called scows), which deposit it elsewhere while the dredge continues its work, and it is also a good gold mining equipment.
A number of vessels, notably in the UK and NW Europe de-water the hopper to dry the cargo to enable it to be discharged onto a quayside 'dry'. This is achieved principally using self discharge bucket wheel, drag scraper or excavator via conveyor systems.
http://www.kedadredger.com/gold-mining-equipment/