National Geographic reports:

Response teams were deploying remote-operated submarines in an urgent effort Sunday to stop the flow of oil from the site of the accident in the Gulf of Mexico that destroyed the BP-leased rig, the Deepwater Horizon.

If the gambit fails, it could take months to stop the leak-now estimated at 42,000 gallons per day of crude oil, according to the joint U.S. government and oil industry task force.

Response teams were deploying remote-operated submarines in an urgent effort Sunday to stop the flow of oil from the site of the accident in the Gulf of Mexico that destroyed the BP-leased rig, the Deepwater Horizon.

The best hope is that the remote-operated submarines-at least four are deployed at the scene–would be able to activate a huge device on the sea floor called a “blow-out protector,” a series of valves meant to control pressure in the well. “This is a highly complex operation,” said Doug Suttles, chief operating officer for BP’s exploration and production division. “And it may not be successful.”

If that operation fails, the next option is to drill a relief well-a process that would take at least two to three months, said Suttles. A BP rig equipped for this task is to arrive at the scene by Monday.

In the above graphic, note the Wildlife Reserves in Louisiana, Mississippi, Alabama and Florida. Also, should the oil become entrained in the Florida Loop Current it could be transported along the Florida Reef Tract, through the Keys and to the Florida east coast. A recent aerial photograph of the oil slick, plus additional images of the Deepwater Horizon blowout can be seen here.

— UPDATE: 1:30 PM PST —

According to the NY Times, “Coast Guard officials said Monday afternoon that the oil spill near Louisiana was now covering more than 1,800 square miles of the Gulf of Mexico, and they have been unable to engage a mechanism that could shut off the well thousands of feet below the ocean’s surface.” Also “The unified command is monitoring the situation and is working closely with officials from Fish and Wildlife, National Marine Fisheries Service and NOAA to understand the impact the spill and response activities may have on whales and other marine wildlife in the area.”