Since 2002, Kerr-McGee has been using regional (several hundred OCS blocks) 3D prestack depth migrations for exploration in Northeast Garden Banks, located in the deepwater Gulf of Mexico (Figure 1). Advances in prestack depth imaging technology, as well as the experience learned in subsalt imaging in the Gulf of Mexico, have impacted ways we evaluate and explore in the deepwater Gulf of Mexico in the past few years. The regional 3D prestack depth migration provided better understanding of the petroleum systems (salt tectonics, sediment fairways, traps, etc.) and reduced exploration risks.