The U.S. Coast Guard is chronicling BP's efforts to contain a massive oil leak 1,524 meters down in the Gulf of Mexico and corral the extensive oil slick heading toward the coast. The oil, as much as 757,000 liters per day, has been spewing into the gulf since April 20, when an explosion aboard the mobile offshore drilling unit Deepwater Horizon destroyed and later sunk the rig.

The Coast Guard is coordinating the response to the underwater oil geyser, although most of the work is being done by booms and skimmers that BP is paying for, a Coast Guard spokesman says. Deepwater was owned by Transocean Ltd. and leased to BP through September 2013.

Another key component of the emergency response is the placement of a four-story, 100-ton concrete-and-steel containment box on the ocean floor over the largest leak, where 85 percent of the oil is escaping. Officials should be able to tell by Monday if the box strategy works.

View a slide show of the cleanup and containment efforts