mudbank

noun

1. An area of mud, possibly submerged, near the edge of a body of water.

   “Before we had gone fifty yards we perceived that all hopes of getting further up the stream in the whale-boat were at an end, for not two hundred yards above where we had stopped were a succession of shallows and mudbanks, with not six inches of water over them.”

   “He had a view across wide fields to the Stour nearing low tide, with its mudbanks emerging from the silver water like the humped backs of monsters, and segrasses and ccircling flocks of seabirds.”