The Gulf of Guinea is the northeasternmost part of the tropical Atlantic Ocean from Cape Lopez in Gabon, north and west to Cape Palmas in Liberia. Null Island, defined as the intersection of the Equator and Prime Meridian, is in the gulf.

The Volta River is the main river system in the West African country of Ghana. It flows south into Ghana from the Bobo-Dioulasso highlands of Burkina Faso. The main parts of the river are the Black Volta, the White Volta, and the Red Volta. In the northwest, the Black Volta forms the international borders between the Ivory Coast, Ghana, and Burkina Faso. The Volta flows southward along the Akwapim-Togoland highlands, and it empties into the Atlantic Ocean at the Gulf of Guinea at Ada Foah. It has a smaller tributary river, the Oti, which enters Ghana from Togo in the east. The Volta River has been dammed at Akosombo for the purpose of generating hydroelectricity. The reservoir named Lake Volta stretches from Akosombo Dam in the south to the northern part of the country, and is the largest man-made reservoir by area in the world.