Massive maritime salvage begins to re-float Costa Concordia
Hunley submarine fully visible
The Kursk submarine disaster, the sinking of the Oscar-class submarine nuclear-powered submarine Kursk, took place during the first major Russian naval exercise in more than ten years, in the Barents Sea on 12 August 2000, killing all 118 personnel on board. Nearby ships registered the initial explosion and a second, much larger, explosion two minutes and fifteen seconds later, which was powerful enough to register on seismographs as far away as Alaska. The Russian Navy did not realise that the sub had sunk and did not halt the exercise or initiate a search for it for more than six hours. Because the sub's emergency rescue buoy had been intentionally disabled, it took more than 16 hours for them to locate the sunken boat.