Integrated Ocean Drilling Program Expedition 308 is an abbreviated form of Integrated Ocean Drilling Program (IODP) drilling proposal number 589-Full 3 entitled "Overpressure and fluid flow processes in the deepwater Gulf of Mexico: slope stability, seeps, and shallow water flow" (available at iodp.tamu.edu/scienceops/expeditions/exp308.html). Following ranking by the IODP Scientific Advisory Structure, the expedition was scheduled by the IODP Operations Committee for the research vessel JOIDES Resolution, operating under contract with the U.S. Implementing Organization (USIO). The expedition is currently scheduled to begin in Mobile, Alabama (USA) on 31 May 2005, departing after a 5 day port call (or when ready). The expedition concludes in Balboa, Panama, on 6 July 2005 (for the current detailed schedule, see www.iodp.tamu.edu/scienceops). A total of 21 days will be available for the drilling, coring, and downhole measurements described in this report. Further details on the JOIDES Resolution can be found at iodp.tamu.edu/publicinfo/drillship.html.