NEW ORLEANS — The Coast Guard is considering setting fire to a large oil spill in the Gulf of Mexico to keep the mess away from shore as efforts to cap a spewing well fail.

That fire could be started today.

Crews have been unable to stop thousands of barrels of oil from fouling gulf waters since an April 20 explosion sank the Deepwater Horizon, which was drilling 50 miles off the Louisiana coast. Eleven workers are missing and presumed dead, and the cause of the blast has not been determined.

Coast Guard Rear Adm. Mary Landry said the controlled burns would be done during the day far from shore. Crews would make sure marine life and people were protected and that work on other oil rigs would not be interrupted.

The burning could start as early as this afternoon, but whether it will work is unclear. Officials would be considering weather conditions including wind and waves in deciding whether to go ahead with the burn, BP spokesman Neil Chapman said today.