Template:POTD/2010-12-19

Source: Wikipedia, the free encyclopedia.
Semi-submersible oil platform
The semi-submersible oil platform P-51, operated by Brazilian energy company Petrobras, being positioned by tugboats. Semisubs sit on pontoons located under the ocean surface, with the operating deck atop columns, above the sea level. In this manner, they are relatively protected from wave action.Photo: Agência Brasil