Here’s your daily dose of science.
Normally the wind can build up waves by pushing on the surface of the water. However, when you add a molecule or two thick layer of oil to the water something very different happens. Because oil molecules are not attracted to water molecules a thin layer spreads out across the top of the water. When the wind blows it pushes against the thin layer of oil which then “slides” across the top of the water. This interesting phenomenon prevents the formation of waves creating a smooth patch around the oil slick.
This might be a neat trick, but we would advise against creating oil spills to prevent wave formation.