Dredgers are responsible for clearing the silt from waterways and rivers so that other ships can pass smoothly. They are also a powerful tool for blowing sand and filling the sea. There are types such as cutter suction dredgers and trailing suction dredgers. The smooth flow of rivers depends entirely on dredgers.

The task of dredgers is to carry out underwater earthwork construction, specifically: deepening, widening and clearing existing waterways and ports; excavating new waterways, ports and canals; dredging the foundation trenches of docks, docks, locks and other hydraulic structures, and throwing the excavated silt into the deep sea or blowing it into land depressions to create farmland.