Oil and oil sheen from the BP Gulf oil spill are seen moving past an oil rig, top right, in the waters of Chandeleur Sound, Louisiana, Wednesday, May 5, 2010. (AP Photo / Eric Gay)

Oil and oil sheen from the BP Deepwater Horizon oil spill are seen moving past an oil rig, top right, in the waters of Chandeleur Sound, Louisiana, Wednesday, May 5, 2010. (AP Photo / Eric Gay)

Disaster unfolds slowly in the Gulf of Mexico