The Red Hook Flats Anchorage in New York Harbor was constructed to accommodate ocean going cargo ships and tankers. It provides a place for ships to anchor off shore. To suit ships of different depths portions of it are 35, 40, and 45 feet deep. Over the years it has been redredged. In 2013 the Army Corps of Engineers, in compliance with environmental laws, announced that it was intending to dredge the flats to maintain the desired depths.
See below for maps of the flats and the complete proposal.