Terrestrial private protected areas safeguard millions of hectares of biologically significant habitats worldwide, but uptake on submerged lands has been limited, due primarily to the erroneous assumption that the oceans are part of the commons and cannot be owned nor leased. In fact, commercial enterprises have been acquiring rights to marine and coastal areas for centuries for fisheries, energy and other uses. Increasingly, by using Marine Conservation Agreements, organisations like The Nature Conservancy (TNC) have begun to acquire similar rights for purposes that safeguard marine resources and benefit local communities. The Conservancy is developing a wide-ranging analysis of the role and feasibility of MCAs in key regions worldwide. This report examines one such region – the Western Indian Ocean (WIO) – and documents findings from an analysis of the ocean and coastal legal frameworks in Kenya, Tanzania, Mozambique, Madagascar, Seychelles and South Africa. An exhaustive synthesis of the laws, policies and practices relating to use and management of coastal resources in the region reveals that MCAs are a feasible strategy in four of the five countries under consideration, and identifies suitable conservation partners. Through an additional analysis of the responses of key opinion leaders in the region, 10 MCA projects are identified and summarised and one detailed case study developed. Finally, the report identifies two limitations that may caveat interpretation of findings and suggests additional focused assessments to satisfy information needs.