Rotating discs are used to attract oil. The collected oil is scraped off and the oil pumped to a collection tank. These units generally float on the surface of the water but larger installations may use fixed units.

A very similar design is the drum skimmer, which utilises a rotating drum rather than an array of discs.

Advantages: Can collect relatively 'dry' oil (~50% water)

Disadvantages:

• Very slow oil skim rate
• Only collects oil that sticks to disc (i.e. many oil types don't stick to the disc)
• High operating and maintenance costs
• Capital cost is high - expensive
• Efficiency and operation affected by debris
• Not very effective at 'pulling' oil into collector
• Some units can drag oil into the water and cause re-emulsification