The Rio del Rey (also called Rio del Ray) is an estuary of a drainage basin in West Africa in Cameroon. It is located in the eastern area of the Niger River system.African Basins. pp. 173-176 The Cameroon volcanic line separates Rio Del Rey from the Douala basin. Rio del Rey has been described as an estuary in which "the two rivers N'dian and Massake flow out".Swedish Ventures in Cameroon, 1833-1923: Trade and Travel, People and Politics - Knut Knutson. pp. 127-133. The mouth is close to the border with Nigeria and has connections to the Cross River estuary from which it is separated by the Bakassi peninsula. The Rio del Rey estuary has been designated as a Ramsar site since 2010.
See also List of rivers of Cameroon
References
Further reading Mangrove Ecosystems: Function and Management. p. 71.