Efforts are continuing in the Gulf of Mexico to stop the oil leak from a US oil rig that exploded and sank last week. Heavy seas however are hampering the works. During a previous attempt, four robotic submErsibles conducted an unprecedented operation to shut the leak with a giant state-of-the-art device. BP plans to collect leaking oil on the ocean bottom by lowering a large dome to capture the oil and then pumping it through pipes and hoses into a vessel on the surface. Around 160 thousand litres of oil is pouring into the sea from the well, causing a massive oil slick that could pose an environmental disaster.