The Rio Muni Basin offers explorers an opportunity to drill in a proven West African play. The basin has delivered over half a billion barrels of new field reserves since the first discovery in 1999. However, more recent exploration has been less successful, suggesting the prospective resource potential may be modest. The key concern for future exploration will be finding sufficient volumes to justify the high development costs for outer shelf and deepwater projects. Development costs are also likely to be high because of challenging reservoir parameters. Our outlook analysis of the Late Cretaceous deepwater play generates slightly negative full-cycle value at Base prices. The economics are sensitive to exploration tax relief. Future discoveries are likely to be small, and accessing spare capacity on existing infrastructure will be one key to success for developers. Full details are available for download in pdf and xls format.