The term 'scrape bottom' is often used to describe a job that requires dredging, which is the process of removing sediment from the bottom of a body of water. Dredging is typically done with a DREDGE, which is a machine that uses a scoop or bucket to remove sediment from the bottom of a body of water. The term 'scrape bottom' is often used to describe a job that requires dredging in order to make a body of water more navigable.