How would this property affect methods an oil spill in the ocean?

The density of petroleum oil is less than the density of sea water. How would this property affect methods an oil spill in the ocean?
That's why it floats on the water and can be collected with large booms on the surface of the ocean - like sweeping a floor. How would this property affect methods an oil spill in the ocean?
Not too sure of what you are asking here, but fuel oil is lighter than water and will therefore float. Eventualy it will coagulate and begin to sink.