Ultra-Large Crude Carrier (ULCC)

The largest crude-oil tanker size class, above 320,000 dwt, sitting beyond the VLCC (200,000 to 320,000 dwt) in the standard tanker tier ladder. ULCCs draw too much water (often 24 meters or more) to enter most ports, so they load and discharge at offshore terminals or by ship-to-ship transfer. Few remain in service; the class peaked in the 1970s, when ships like the Seawise Giant exceeded 560,000 dwt, before the trade favored the more flexible VLCC. They serve long-haul Gulf-to-East or Gulf-to-US routes.