The Delaware Bay is bordered by the states of New Jersey & Delaware and reached depths of more than 150ft. It mixes fresh water with the salty brine of the nearby Atlantic Ocean and is part of the second most travelled maritime trade routes in the United States.

The Delaware Bay is a relatively shallow estuary, but its depth varies significantly between its flanks and the main shipping channel. The average depth is approximately 26 feet (8 meters). However, the bay features a deep, centrally located natural and dredged channel used by massive tankers heading to Philadelphia and Wilmington; this channel is maintained at a depth of about 45 feet (13.7 meters). In certain areas near the mouth of the bay, natural scouring can create depths of up to 148 feet (45 meters). Conversely, much of the bay consists of vast, shallow tidal flats and shoals that may only be a few feet deep at low tide. This extreme variation makes navigation tricky for recreational boaters, who must stay strictly within marked channels to avoid grounding on the "benches" that line the deeper waters.