After two failures. Rescuers launched a third attempt on Wednesday morning to reach the 116 sailors trapped in a Russian nuclear submarine on the bed of the Barents Sea.
The Crew of the damaged Oscar II class submarine Kursk, which sank when they shut off the reactor after an accident at the weekend, have just 48 hours of oxygen left.
At least two rescue capsules, each capsules capable of evacuating 20 people at a time, are attempting to dock with escape hatches on the stricken submarine.
Two 400-tonne inflatable pontoons could lift the vessel from the seabed either to the surface or to a depth where scuba divers can operate.
Britain is sending a submarine to help the rescue effort. The LRS has a crew of three and can rescue 16 people at a time.