Hundreds of boats are battling to contain the giant oil slick that's threatening the US Gulf Coast. Oil has been gushing from an undersea well for almost two weeks since the BP rig, Deepwater Horizon, sank after an explosion. +++LM-REIN+++ Crude oil has already washed ashore in Louisiana, and could reach Mississippi, Alabama and Florida by Monday. The spill is well on its way to becoming the worst environmental.. +++LM-RAUS+++ disaster of its kind in the US. And has become top of the agenda for Washington.