Dredging

Dredging is the underwater excavation of seabed material to create or maintain navigable depth and to win fill for reclamation. Capital dredging deepens or widens a channel or basin for the first time; maintenance dredging removes the sediment that continually re-deposits. The trailing suction hopper dredger is the workhorse for maintenance and sandy capital work, while the cutter suction dredger handles harder material. Disposal of dredged spoil is regulated under the London Convention and Protocol against marine pollution.