The deposition/accumulation of oil on the seafloor is heavily influenced by sediment/texture/composition and sedimentary processes/accumulation rates. The objective of this chapter is to provide a baseline of Gulf of Mexico sediment types and transport/depositional processes to help guide managers where oiled sediments may be expected to be deposited and potentially accumulate on the seafloor in the event of a future oil spill. Based solely on sediments/processes/accumulation rates, regions most vulnerable to oil deposition/accumulation include the deep eastern basin, followed by the western/southwestern basin, and north and west continental margins. The least vulnerable regions include the northwest Cuban shelf and the carbonate-dominated west Florida shelf and Campeche Bank. This is intended to be used as a general, “first cut” tool and does not consider local variations in sediments/processes.