distributary of the Niger River in the western Niger delta, southern Nigeria. Its 35-mile (56-kilometre) westerly course traverses zones of mangrove swamps and coastal sand ridges before entering the Bight of Benin of the Gulf of Guinea. There are no ports on the river, but the Escravos is linked by a maze of interconnected waterways to the Forcados, Warri, Benin, and Ethiope rivers. By 1960, although the natural passageway over the Escravos Bar at the ocean exit was only 12 feet (4 m) deep, the river had already supplanted the Forcados as the main approach to the Delta ports: Warri, Burutu, Sapele, Koko, and Forcados. Since the completion in 1964 of the Escravos Bar Project, the Escravos has provided the only route for oceangoing vessels to those ports. There is also a petroleum-shipping station serving a submarine oil field 11 miles (18 km) offshore from the mouth.