An oil spill skimmer and processor particularly for offshore oil spill recovery includes a series of features which enable efficient recovery of oil from the water surface, even in the presence of considerable debris. Controllable water jets move the oil generally by means of a mound at the water surface, entrapping air which rises and moves the water outwardly. Debris can be steered away by the use of a water jet on one side of the inlet to the apparatus. A further water jet adjacent to a front weir of the skimmer system enables cleaning of debris from the weir itself. Preferably a nozzle is included at the back of the apparatus for the introduction of chemicals into the oil. Further, the apparatus enables the operator to reverse either of two internal pumps to flutter weirs up and down for the clearing of debris. A debris grid or grate at the inlet of the skimmer apparatus traps debris, and a grinder receives trapped debris from the grate. Ground up debris is passed on with the recovered oil. The apparatus further includes fore and aft ballast tanks with ballast control, for adjustment of the attitude of the vessel to compensate for waves. The system includes controls allowing shifting of the operating positions of the front and rear weirs. Baffles are included near a front sump to assist in oil/water separation.