A four-story metal container designed to slow an oil well leak at the bottom of the ocean. The dome is lowered over the oil leak on the ocean floor with the purpose of capturing the oil so it can be pumped up to the surface.
"The first containment dome left the dock at Port Fourchon, Louisiana to head out to the well site. This system is designed to help capture the oil at the seabed and collect it securely for processing." - BP 5/6/2010