The design, construction, and testing of, an oil skimming and separation system capable of processing 30,000 gallons per hour, and operating on the open ocean under Sea State 3 conditions is described. A 45 x 26-foot twin-hulled barge, which contained an entrance paddle wheel and self-adjusting skimming weirs, was built to support the skimming and separation equipment. A 500-gpm centrifuge was used to reduce the oil content of the discharge water to less than 100 ppm. The recovered oil contained less than 5 percent water. The oil content of the discharge water could be reduced to less than 20 ppm by recycling it through the centrifuge a second time. Intentionally spilled oils of API 15, 26, and 35 gravities were recovered and separated, as were weathered oil slicks. The centrifuge was particularly useful in separating the mixtures of water and the higher API gravity oils.