The U.S. Army Corps of Engineers defines dredging as “A dredge is a machine that scoops or suctions sediment from the bottom of waterways…”
Although companies are using the ‘Coanda effect,’ it is still dredging. The leading dredging companies have built polymetallic nodule collection systems, e.g., All Seas, DEME/GSR, Royal IHC, etc. Dredging tractors for deep sea mining were first described in a 1965 patent, 3,456,371.
