The US GoM Deepwater Gulf Coast Tertiary basin has a decades-long history of exploration and development, with close to 25 bnboe of resource found. While the region is highly prospective with significant remaining volume potential, it has been a challenging area to create full-cycle value because of high costs. With limited opportunity left in the shallower plays, explorers are operating in more technically challenging and costly environments. Improvements in technology, in seismic imaging and deepwater rigs in particular, have allowed operators to explore previously unseen and unreachable targets. Massive resource potential exists in the Subsalt Miocene, Paleogene (Lower Tertiary) and Jurassic plays, although all have numerous geologic and engineering complexities. However, the industry's recent success in reducing both exploration and development costs should see a return to positive value creation in the basin. Full details are available for download in pdf and xls format.