BP has major contracts with two national companies to clean up any major spill at Deepwater Horizon: the nonprofit group Marine Spill Response Corp., based in Herndon, and National Response Corp., a wholly owned subsidiary of Seacor Holdings, based in Fort Lauderdale, Fla.

They, in turn, hire other contractors to help with deploying vessels, booms and aircraft for spreading chemical dispersants. Seacor, which also worked on the recovery effort in Haiti, also owns O'Brien's Response Management, which is lending employees who act as added managers and advisers for BP in Houma, La., and Mobile, Ala.